CABLE: 1) Any piece of wire with connectors at either end, used in interconnecting different A.V. components. A grouping of wires in a protective sheath used for the transmission of electrical power and-or signals. 2) See CABLE TV.
CABLE DTV: See CABLE TV.
CABLE LABS: Short for Cable Television Laboratories, Incorporated of Louisville, Colorado. Telephone number 303-661-9100. The agency formed by major cable television providers to develop standards for cable to provide Digital TV (DTV), Interactive TV (iTV) and cable telephony (the ability to make personal phone calls via one’s cable TV service).
CABLE MODEM: See MODEM.
CABLE MSO: See MSO.
CABLE REFLECTION: Wire (cable), as it transmits a stream of electrons can tend to actually reflect some of the electrons back into the stream causing ripples and distortions, similar to how water flows and eddies in a river: the disturbances caused by the river bank, cause “reflections” of water to flow back out into the main stream of water producing disturbances in the flow. Poorly soldered or inferior connectors can also cause cable reflections. This is a situation more common in video and computer transmission.
CABLE-SATELLITE PUBLIC AFFAIRS NETWORK: See C-SPAN.
CABLE TRUNK: 1) A group of cables harnessed together into a bundle, forming a “trunk” of cables. 2) A large container that holds cables. A trunk is used for storage and shipping of cables.
CABLE TV, CABLE DTV, DIGITAL CABLE TV: A method of sending television to consumer’s homes via a cable (wire), usually underground. The cable is run right into the consumer’s home and hooks to his TV equipment via a receiver box, called a “set-top box” (because it can be set on top of the TV). The cable TV provider runs a centralised transmission station that branches out to local area homes. Often a cable TV picture is better than antenna reception in remote locations or in cities where large buildings prevent acceptable use of antennas. Digital Cable TV can be provided via fibre optical cable and be significantly improved in terms of quality and speed compared to existing cable TV services. Cable DTV combines many digital services - many of which cannot be done by satellite. For example, a home consumer, via his Cable DTV hook-up, is able to receive full Digital TV including High Definition programmes, high-speed Internet access, Video On Demand (the ability to select what movie video he would like to watch and when), Interactive TV, and even the ability to make personal phone calls right over the fibre optic cable. AOL Time Warner is the largest cable provider, but there are many others such as “Respond TV”, “Comcast” and “Two Way TV” (in the UK).
CABLE TV TUNER, RECEIVER: Cable TV can provide High Definition TV programming via their network lines to homes and businesses. Many High Definition TVs sold before 2001 have no capability for being hooked up to a cable TV provider’s feed as the methods to receive such were not worked out until after January 2001. HDTVs sold after 2001 have the needed electronics and connection points to receive Digital TV (both cable and satellite). Two different types of tuners are available. One is for local TV broadcasts in High Definition or digital. These stations do not have scrambled feeds to homes and the tuners are usually built right in to the TV for such reception. Other Digital TV broadcasting via cable is paid-for subscriptions and is scrambled to prevent unauthorised reception and copying.
CACHE: The word “cache” comes from Latin meaning, “to stow away”. In computers, a cache is a special memory system in addition to the computer’s Random Access Memory (RAM). A memory cache stores data that is frequently accessed by the user and makes it available very quickly. It operates at the speed of the computer’s main processor and is always faster than RAM - though it does not store as much data as a RAM can. For example, if one has an often-used list of telephone numbers in a computer, the cache will store those numbers. Then, when he or she wants to see the list, the cache will display it much faster than the RAM will. When the user accesses information on his computer, the cache “looks” to see if it has the information in its memory. If it does it dishes it up immediately and if not the RAM is used.
CAD: Abbreviation for Computer-Aided Design. A computer programme used to design (draw) engineering, architectural and scientific models. CAD programmes and designs done using such range from very simple to the complex designs of buildings, electronic circuits and even aircraft and spacecraft. CAD designs can be skeletal drawings or can consist of several layers of 3-dimensional, full-colour representations.
CALIBRATED: It is vital in producing an audio programme that the equipment used be tested and adjusted to meet the exact standards required to produce a high-quality product before it is used for the production of that product. Audio technicians, engineers and equipment operators use “test tones” to do these tests and adjustments. When the adjustments are done, the equipment is said to be calibrated. “Calibrate” means to adjust and standardise a piece of audiovisual equipment to its optimum mechanical and electronic performance. This is based on exact and agreed-upon industry standards or manufacturers specifications and is done routinely by technicians and operators. When a piece of equipment is “calibrated” it is precisely adjusted to meet required standards. Examples of studio items that are calibrated include meters, tape recorders and video monitors (TVs). Calibration is done to establish and maintain the quality of a studio’s products.
CALIBRATION: 1) In tape recorders, the setting of all controls and adjustments for optimum performance. 2) To adjust a meter or testing device to be as accurate as possible.
CALIBRATION TEST TAPE: “Calibration” means adjusting and standardising a piece of audiovisual equipment to its optimum mechanical and electronic performance. A “calibration test tape” is a standardised magnetic audio tape manufactured by professional reference laboratories which have recording equipment of verified accuracy. Such test tapes are recorded in a variety of sizes ranging from cassettes to 2-inch wide studio recorder tape. These tapes contain a series of tones recorded at an EXACT volume which are used as a standard calibration reference. The combination of a recorder’s moving parts and electronic circuits working properly together determine its precision. Calibration test tapes are used to establish and maintain that precision.
CAMAC: See CONNECTORS TYPES OF.
CAMCORDER: Short for camera-recorder. A “camcorder” is a video camera which has a tape recorder directly attached to it as part of one self-contained unit. These units record both video and audio onto a tape or other storage medium. There are many different brands and types of camcorders available, from home consumer (amateur) quality all the way up to top professional level.
CAMLOCK: See CONNECTORS TYPES OF.
CAMERA-LEFT: The left side, as viewed from a camera view of the stage (as differentiated from STAGE-LEFT, which is from the perspective of a performer on stage looking out at the audience).
CAMERA MASTER or BETA MASTER or DigiBeta MASTER: The actual videotape recorded from the camera’s direct signal when the shot was taken. It is the master, original image recording. Usually also has sound. (“Beta” and “DigiBeta” are trademarks of the Sony Corporation.) Note: During some shooting situations, particularly at major events, often the tape is not put in the camera itself, but rather the camera’s signal is routed to its own professional videotape recorder. Nonetheless, the recorded tape is still referred to as “the Camera Master”.
CAMERA-RIGHT: The right side, as viewed from a camera view of the stage (as differentiated from STAGE-RIGHT, which is from the perspective of a performer on stage looking out at the audience).
CAMERA TWO: The main camera at a live event. It is the one which photographs the main speaker at the podium straight on. It creates the shot you watch the most in a videoed event.
CANARE CABLE: Canare is a manufacturer of wire and connectors for audio and video applications.
CANNES FILM FESTIVAL: A film festival held in the French town of Cannes once a year. Films from all over the world are presented and receive awards, often before they are released for general public viewing.
CANS: A slang term for “headphones”.
CAP: Short for CAPACITOR. See CAPACITOR.
CAPACITANCE: “Capacitance” comes from the word “capacity”, which means the ability to receive, hold or contain. It is the measurement of how much electrical charge can be stored by something. The basic unit of capacitance is the “farad”, which is named after English physicist Michael Faraday (1791 - 1867). Faraday worked with quantities of electricity much larger than those required by most modern electronic circuits but the basic principles he used are still applied. In its use in electronics today, the “farad” is usually prefixed by “micro” (one millionth), “nano” (one billionth) and “pico” (one trillionth) to indicate the amount of capacitance in audiovisual equipment.
CAPACITOR: If you open up almost any piece of electronic equipment you’ll see lots of small parts attached to circuit boards. Included in these are “capacitors”, which store electricity. One of the main uses of a capacitor in a circuit is to supply a smooth flow of electricity to the rest of the electronic parts in the circuit. The capacitor receives electricity, stores it, and only allows it to leave when it meets an exact specified amount. It also can make the electricity smoother (fewer distortions). This allows the circuits inside electronic equipment to operate better and more stably. Capacitors come in many different types, shapes and sizes. Inside, a capacitor has two metal plates held apart by a rigid base. The reason a capacitor can store electricity is that its two plates are held apart. There are then two stable terminals (plates) which can receive and send a flow of electrons. If the plates were allowed to touch each other the electricity would just flow through as if the capacitor were a piece of wire, and its storage capability would be defeated. Generally, the amount of electricity they can store is directly proportional to the size and the proximity of their plates.
CAPACITY: In compact discs, the term “capacity” refers to the capacity of any type of CD or DVD to hold data. cd’s can normally hold up to 74 minutes while a DVD, and the way pictures and audio are recorded onto it, can hold an entire movie. Any computer has data storage “capacity.”
CAPSTAN: On a tape recorder, the motor-driven shaft that drives the tape past the heads at a constant speed. A rubber roller presses the tape between itself and the capstan. The capstan and rubber roller rotate so as to move the tape smoothly and at a very consistent speed.
CAPSULE: A microphone capsule. This term is used to refer to that part of a microphone which contains the element that picks up the sound vibrations from the air. Some microphones have capsules which can be detached and interchanged with other capsules for different recording applications.
CARD: Short for circuit card, which is a flat board with electronic components on it.
CARD CD: A small CD, intended for use as a type of “business card”. They are meant for 2 to 3 minute audio data marketing presentations. They will play in any CD player except for those types of CD players, common in cars, where there is a narrow slot in which the CD is inserted. The small card CD is not large enough to be grabbed by this type of player’s mechanism for its insert and eject functions. The cards are produced as a read-only memory (ROM) CD at normal CD rates.
CARDIOID MICROPHONE: A microphone with a pickup pattern that has maximum pickup up from the front, less pickup from the sides, and least pickup from the back of it. If this pickup pattern is drawn, it has a heart shape.
CARRIER WAVE: An electronic current or signal (a wave) that cam be modulated (varied) by another signal. A radio or TV broadcast station will use its music, speech or TV picture’s signal to modulate the carrier wave. The wave then carries the modulations to one’s radio or TV set. When received, the radio or TV “looks” at the carrier wave. The radio or TV then reproduces just the modulations to create sound and pictures. A carrier wave is used for the E-Meter’s operation similar to how radio and TV also use carrier waves. See the EM-4 film and the book, “Understanding the E-Meter” for the full technical information on what a carrier wave is and how it works. If you were to think of a radio station sending out a communication, the carrier wave could be compared to the “intention” part of the Comm. Formula. It is carrying the station’s communication.
CAR SURROUND SOUND: 5.1 surround sound loudspeaker systems for cars, boats, etc. A Dolby surround sound system can now be installed in cars.
CART (a “cart machine): An abbreviation of cartridge, referring to a recording tape’s cartridge (its outer shell). The term cart is specifically used as regards the type of small tape cartridges used in TV and radio broadcasting. They are square shaped tape cassettes and rapidly wind or rewind to the desired programme. Cart machines have mostly been replaced by digital machines that store the audio digitally inside the unit for instant access, instant start-up, and instant repeatability.
CARTRIDGE: (See PHONO CARTRIDGE.)
CARVIN: A company that builds all kinds of guitars and related equipment as well as PA equipment.
C.A.S.: Abbreviation for Cinema Audio Society. C.A.S. is a Los Angeles based organisation of film and television recording personnel founded in 1966. Its membership includes Recordists, Mixers and other specialists who work in the film and TV audio industry. It is similar to the American Cinematographers Society for cameramen, lighting personnel, etc. Industry professionals often put the initials of these associations after their names.
CASSETTE: A small plastic magazine for holding a reel of magnetic recording tape, designed to be inserted into a tape player, played and rewound without removing the reel or the tape.
CASSETTE DECK: The tape player that an audio cassette is played on.
CAT. 5 (WIRE): “Cat” is an abbreviation for the word “category”. Category 5 wire is a type of wire commonly used to hook computers together between two or more locations.
CATHODE: 1) The negative electrode (terminal) by which current leaves a battery or similar electrical storage unit. The word “cathode” comes from the Greeks - it meant “the way down”. (Note: See ANODE for a simple explanation of electron flow in an electronic circuit.)
2) The negative terminal, electrode or element of a vacuum tube. (VACUUM TUBE is defined separately.)
CATHODE-RAY TUBE: (Abbreviated CRT) All conventional TV tubes are technically called “cathode-ray tubes”. It is a vacuum tube in which an electron beam can be focused onto a small cross-section on a luminescent screen and can be varied in position and intensity to produce a visible pattern (the picture you see on TV). (See CATHODE.)
CAV and CLV: Abbreviations for Constant Angular Velocity and Constant Linear Velocity. Magnetic and optical data storage discs can rotate with constant ANGULAR velocity or constant LINEAR velocity. In systems using constant angular velocity (CAV), the disc rotates at the same speed always. The pickup head that is reading the disc travels over a longer distance as it moves from the centre of the disc to the outer edge. In the CAV method, the same amount of information is provided per each rotation. In constant linear velocity systems, the pickup head moves over the disc at a constant speed, requiring that the disc’s speed of rotation speeds up or slows down as the head travels toward or away from the centre. For example, a CD-ROM spins from 539 rpm when the pickup head is at the inner edge, slowing to 210 rpm when it reads the outer edge. In the CLV system, the amount of data per unit of length of disc remains constant. This allows more data to be stored on a disc than the CAV method.
CCD: Abbreviation for Charge Coupled Device. This is a term used in regards to video cameras. CCD’s are light-sensitive elements inside the camera. Light is converted into an electrical charge proportional to the amount of light hitting each cell of the device. The cells are coupled to a scanning system that, after analogue to digital conversion, presents the image as a series of binary digits. Early CCD’s were unable to reproduce a wide range of brightness, but they now offer low noise high resolution imaging, beyond current broadcast television resolution. Defect-free CCD cameras are now produced for shooting High Definition formats.
CCI: An abbreviation for Copy Control Information. Digital data that is part of the content creation process, designed to prevent unauthorised use of A.V. programmes. There are four different settings possible: Copy Free, Copy Once, Copy No More and Copy Never. Each one of these settings dictates how the output of playback device will operate. Copy Free is unrestricted as to how the content will be displayed and-or recorded - although this does not authorised pirate copying, which is against the law. Copy Once allow the user to make a single copy. Once that single copy is made, the digital code in the programme changes to “Copy No More”, meaning no further copies can be made. Copy Never allows no copying whatsoever.
CCIR: Abbreviation for Comite’ Consultatif International Technique des Communications Radio Electronique. (The International Radio Consultative Committee.)
CCITT: The Consultative Committee International for Telegraphy and Telephony, established by the United Nations within the International Telecommunications Union (ITU), is based in Europe, and recommends worldwide telegraph and telephone (including fax) transmission standards.
CD - the Compact Disc, what it is: The Compact Disc was developed by Philips and Sony, and was first implemented only for storing (archiving) digital audio data before it was put to use for music industry releases and distribution in the early 80’s. In 1982, Sony and Philips finalised the “CD Digital Audio disc” (CDDA). This is what is known today as the “CD,” or “Compact Disc”. It can hold upwards of 74 minutes of two channel stereo audio. The most common disc is 4¾ inches across (12 centimetres). Some smaller CD’s exist (3 inches across) that only hold 20 minutes of sound. A CD’s digital information is embedded (stamped) into the plastic inside the disc and then a very thin layer of aluminium coating is applied on top of that stamping, and yet another layer of plastic is applied on top of that (on top of the aluminium) to fully form the CD. The music (or lecture) on a CD is broken up, by computerisation, into 44,100 “segments” each second. These segments are called “samples.” A sample is somewhat akin to a “snapshot” taken of the sound 44,100 times EVERY second, and each of these samples contains 16 bits of data. Each individual sample is then converted into a “digital code.” This code uses the Binary number system and is represented on the CD by billions of microscopic “pits” that form a spiral track moving outwards from the centre of the disc. As the disc spins in a CD player, a laser beam follows the track of pits. The light reflects off the CD, and a light-sensitive device turns the different reflections into electric signal pulses. These signals correspond to the original digital code. An amplifier then strengthens the signals and eventually they are reproduced loudly enough to be heard over loudspeakers or headphones. (Further data at CD’s HOW THEY ARE MADE AND HOW THEY WORK.)
CD’s and DVD’s CARE and CLEANING: Though they are quite hearty, audio and picture quality suffers greatly due to mishandling, abuse and failure to keep digital discs clean. Fortunately, when a CD or DVD is played, there is no friction (rubbing of the disc) as only the laser’s light beam ever “touches” its surface. Therefore, playing does not create wear, no matter how often the disc is played. A disc will last many years if cared for properly. Any time a CD or DVD is not being played, they should be returned immediately to their case, or proper storage. Hold the discs by the edge and place them immediately into the machine, or return them directly to their protective storage. Never leave discs laying out. Cleaning a CD or DVD is simple. Use a very soft cotton cloth and a dab of diluted ammonia. Don’t wipe in circles around the disc. Instead, wipe across the disc going from the inside to the outer edge. If the disc ever becomes scratched for some reason, it is possible to remove those not too deep. (There are several brands of rubbing compound specifically for digital disc scratch removal. Any Office Depot or Staples Office Supply carries the product.) Scratches, as well as dirt and smudges, affect the laser’s ability to read the information inside the disc. It is usually thought that the bottom of the disc (the non-labelled side) is the most important surface to protect from dirt and scratches. It is very important to do so. However, the top (the printed side) is the most sensitive! The bottom side is called the “reflecting side” (the aluminium coating is more shiny on the bottom side than the top of the disc). The reflecting side of the CD is the side that is read by the player’s laser. But the more vulnerable side is not the reflecting side but the label side (the top side). The top only has 0.002 millimetres of plastic over the aluminium coating inside the disc. Granular dust and sand can cause small scratches or hair cracks in the top, enabling air to penetrate to the disc’s interior aluminium coating. The coating then starts oxidising at that spot and the disc will become ruined. It is therefore better to store CD’s with the reflecting side down and the printed side (the top) UP. If the laser cannot read a portion of the disc’s digital information, due to scratches, smudges or dirt, that portion will be skipped, or distorted. Digital discs and disc players are designed to provide some amount of “error correction.” Error correction can detect missing bits of data not read off the disc and, by computerisation, approximate what digital information should have been there, and provide such so no skip in the music or lecture programme is heard. Of course, it’s best to keep the disc clean and non-scratched, instead of depending on error correction. Lastly, never bend a disc unduly, even when taking it out of its case. Bending causes stress fractures. Also, the aluminium coating inside the disc can become deformed, preventing some information on the disc from being read by the player’s laser beam. As a consequence, error correction will always have to be applied in that area of the disc, affecting its final sound. And, never write on the label side, even with a felt-tipped pen. The ink may penetrate the thin protective coating and affect the aluminium layer. (An exception to this are recordable CD’s that have a top layer specially designed to be written on with a marker.) In summary, any smear or scratch or mark on a disc, however small, can cause information to be lost. Keep the discs perfectly clean and well cared for (no scratches) and best sound and image quality is assured.
CD’s: how they are made and how they work: There are many production steps involved in producing a Compact Disc and it is important to understand the process. As well, by knowing how a CD is made, it is also possible to fully understand how the Compact Disc actually creates music when played in a CD player. The list below contains, in sequence, the basic steps involved in producing a CD, after which follows a description of how a CD is then able to produce music. (Note: DVD’s are produced and work similar to CD’s, but there are additional steps and information applicable to the DVD manufacturing process and how DVD information is played back. See DVD’s HOW THEY ARE MADE AND HOW THEY WORK.)
All technical words and terms below may be found defined elsewhere as entries in this glossary
How A C.d. Is Made
1) First, final preparation of the audio programme is done. This step is called “mastering,” but is not to be confused with later steps in the CD manufacturing process which are also called “mastering” and involve the making of mouldings with which to produce final CD’s in volume. This “first” mastering step, done by audio personnel, performs various final adjustments and handlings to the audio, especially ensuring the programme’s volume levels are consistent throughout and set for best digital performance. When all adjustments are complete, the audio personnel supply a “Plant Master” - a high quality digital copy of the audio that usually also includes all index and timing codes (so the consumer can see “Track 1,2,3, etc. in the CD player’s display window). These codes are called “PQ Codes” and are either included on the Plant Master itself, or in writing for inclusion on the CD disc when it goes through its replication process as described further below. The Plant Master can be in several forms. For lectures, an Exabyte tape is produced from the SADiE computer system in the Audio Building. For a music CD, the Plant Master may be produced by an outside Mastering Engineer, in which case a type of digital video tape may be used called a “1630” (made on Sony’s model 1630 machine), or a recordable CD, or even an Exabyte tape - depending upon the approved production line for CD music discs.
(The final Plant Master is digital, meaning the audio information it contains is a unique sequence of binary numbers for that specific audio programme.)
2) The Plant Master is then sent for “Glass Mastering”. This is done by a company which specialises only in glass mastering or by a CD replication facility that does glass mastering in addition to running mass volume CD’s on replication machines. Though the process is called “Glass Mastering”, and is often spoken of in terms of “creating a glass master”, in reality, there are many steps and masters created to full prepare to mass duplicate (“replicate”) thousands of consumer CD copies of the audio programme. (It should be noted that if the Plant Master did not digitally include the needed index and timing PQ codes mentioned in step 1 above, then the company doing the glass mastering will need the codes in written form as they will include such on the glass master itself, and additionally charge you for doing so. This also includes any copy protection codes requested.)
3) In the first step in glass mastering, a glass disc that has a light-sensitive coating is used. The glass master is bigger than a CD, being 8 inches (200mm) in diameter and about 6mm inch thick. The coating of light-sensitive material is 150 microns thick and its uniformity on the disc is very important. The coating is baked onto the glass which also makes the coating very hard. A laser is then aimed at, and “fired” at the glass disc. (Actually, it is fired at the light- sensitive coating on the glass.) The laser shoots in bursts. Its beam is “modulated”, meaning the laser is started and stopped by being instructed how long to fire and how long to remain unfired, based upon the Plant Master’s digital Binary number information. The Plant Master’s different Binary numbers each cause the laser to start and stop firing differently. In this way, the laser’s “pulses” actually create an exact representation of the Plant Master’s Binary information on the light-sensitive coating. When the laser’s light is “on”, a tiny spot on the light-sensitive coating is “exposed”. Where the laser is “off”, the coating remains unexposed. The glass itself is unaffected by the laser, only the coating is affected.
4) The light-sensitive coating on the glass is actually called a “photoresist coating”, meaning that wherever the coating was NOT exposed to the laser’s light, that part of the coating will later “resist” being removed or rubbed off from the glass master. Therefore, after the coating has been “shot” by the laser, it is then processed, similar to how photographic film is developed, and anywhere the coating was exposed (“shot” by the laser), the coating is made to disappear. In other words, where the coating was exposed to the laser’s light pulses, the coating is removed. This leaves small microscopic “pits” in the coating right down to the glass. And, the unexposed areas of the coating remain on the glass.
5) The unaffected coating areas exist between the pits and are called “lands”. Therefore, it can be said that “pits and lands” are formed on the surface of the glass master disc, right in the coating itself. For every C.D., there are some 2 billion pits created by this process. The pits and lands vary in length. This is because the original Binary information coming from the Plant Master tells the laser to remain “on” (or “off”) for different lengths of time. As such, a unique pattern of pits and lands, each with different lengths, is created which corresponds precisely to the unique Binary number information from the Plant Master. (Later, after the final cd’s are made, this pattern of pits and lands will be read back by a consumer’s c.d. player to once again create the original Binary number information that was provided by the Plant Master. Binary information is easily converted to sound - the conversion process being the whole basis of digital audio and explained in more detail in later steps below.)
6) Next, a layer of metal is then gently created over the glass master’s coating of pits and lands. Electrolysis is used - electricity allows molecules of the metal to build up over the glass master. (Another similar process, called “sputtering”, is sometimes used as well.) No heat is involved. The metal coating is allowed to thickly build up before it is removed from the glass master.
7) This metal coating is now called the “Metal Master” or, more commonly, the “Father”. It is an exact duplicate of the pits and lands created in the light-sensitive coating on the glass disc. However, the metal Father is actually opposite, meaning a negative image of, the original glass master. (Like a print of your hand in mud, the Metal Master - the Father - has an opposite imprint of the glass master’s pits and lands. The Father is therefore said to be a “negative image” of the glass master.)
8) The Father is then used to create a “Mother”, similar to how the Father was produced. The Mother is an exact copy, made of metal, but it is an opposite image of the Father.
9) The Mother is then used to make “Sons”, using a similar metal coating (plating) procedure. Each Son is a negative image, exactly copying but opposite to the Mother. More than one “Son” is made, as Sons are the actual Stampers used to “stamp” (mould) the thousands of final c.d. copies for consumer release.
10) The full “glass mastering process” is now complete. (The glass disc, upon which a light-sensitive coating was turned into a pattern of pits and lands by a laser, has been used to create a Father, then a Mother, then Sons (“Stampers”) to be able to produce the thousands of cd’s sold to public.)
Note: A Father or a Son can be used as a Stamper. Both are made of metal and both have a “negative image” of the original glass master. While the Father may give just a bit better sound quality than a Son (the Father is a direct copy of the original glass master), it is a fact that Stampers can only create a certain number of CD’s before they become worn. By having and using multiple Sons, more final CD’s can be produced without having to repeat any glass mastering steps.
11) Now the cd’s can be replicated in volume. To do so, the Stamper (a Father or a Son) is mounted in a moulding press. Hot melted plastic is injected and the plastic takes the form of the Stamper. (This will be the final CD the consumer can play at home.)
Note: Because the Stamper has a negative image of the glass master’s pits and lands, and the moulded c.d. is an opposite (mirror image) of the Stamper, the final c.d. actually has a positive image, just like the glass master created by the laser originally.
12) Each final c.d. is finished by applying several successive layers upon the new moulded (“stamped”) plastic. One layer is a thin coating of aluminium which is used to reflect the laser beam within c.d. players that will eventually play the disc. Other layers are also applied to bring the c.d. to its final form, including a protective layer of plastic over the aluminium, creating the top surface of the c.d. upon which label printing is then added.
NOTE: It is actually the top, where the printing is located, that is the most sensitive part of the final c.d.. (Most consumers think the bottom, where the laser strikes, is the most important side to protect from scratching. However, it is the thin top protective layer just above the aluminium that is the most sensitive.) If the thin protective plastic coating (just below the printing on top of the disc) becomes scratched at all, molecules of air and impurities can work their way inside the c.d. and deteriorate the aluminium, thus harming its reflectivity and degrading sound quality. There is far more plastic on the bottom of the c.d. so it is not so susceptible to allowing aluminium deterioration. However, deep scratches on the disc’s bottom, as well as dirt, oils and smudges, can block the laser from fully reading the disc and so the bottom must be kept clean and undamaged as well. Also, bending the disc severely can distort the aluminium coating inside the c.d. thus degrading its sound. In summary, owners of a c.d. should take care to ensure the disc is never scratched on its top (the printed side) as well as the bottom and that the c.d. is never bent. (See cd’s and DVD’s CLEANING AND CARE for more information and technical data concerning disc storage, care and cleaning.)
NOTE: For technical personnel involved with producing cd’s, much information may be found in the book “PRINCIPLES OF DIGITAL AUDIO”, by Ken C. Pohlman, published by Sams.
How A C.d. Works
When a c.d. is placed in a c.d. player, a laser strikes the disc as it spins. The laser starts from the centre of the disc and moves outwards (opposite to how a vinyl record album is played on a phonograph). It is important that the laser beam read the disc at a constant unchanging speed, but due to the disc being smaller towards its centre with its diameter increasing towards its outer edge, the disc’s rotational speed must change as the laser moves outward. The disc is therefore rotated 500 times per minute when the laser first starts, and as it moves across towards the outside of the disc, the disc’s speed is steadily slowed to only 200 rotations per minute. The pits and lands of the c.d. exist in a continuous line spiralling tightly out from the centre of the disc. There are about 20,000 lines on a c.d., which are really just one long line spiralling outward. (If the line of pits and lands were to be “un-spiralled”, it would stretch about 5km.) The line is 30 times more narrow than a single human hair and consists of a pit, then a land, a pit, then a land, etc., continuing all in a row. (If a CD were enlarged so that its pits were the size of grains of rice, which is roughly how pits are shaped (running length-wise), the disc would be ½mile (0.8km) in diameter!) Each pit and land is a different length, forming a combination that corresponds to the original audio information. As the laser beam travels along the pits and lands towards the CD’s outer edge, it reflects off the bottom of the pits and the surface of the lands. These reflections are received by an optical sensor (a light sensor) located inside the CD player. The light sensor converts the laser’s reflections to electrical pulses, and those pulses are then converted to music (or a lecture) by other electronic circuits also located inside the CD player. But realise that when a CD is played, it is actually played “upside down” compared to the original glass master! The laser is actually looking through the “bottom” of the CD, at the backside of the pits and lands. (Remember, the CD’s “top” is where the printing is yet the laser fires at the CD through the other side; its bottom.) Therefore, the pits are actually upside down as seen by the laser. In other words, the pits are raised, not sunken, as viewed by the CD player’s laser beam. And, because the pits are raised, the edges of each pit create tiny ridges, like a mountain’s cliff walls. The laser’s light reflects back easily all in one direction when it strikes only the flat horizontal surface of a land, or just the bottom of a pit (actually it’s the “top” of each pit - remember that the CD is being played “upside down”!). But when the laser beam strikes a pit’s edge (technically called a “ridge”), the surface of the ridge is at a vertical angle to the beam. The ridges are right where a land ends and a new pit starts and where a pit ends and a new land starts. The laser’s “ridge reflections” go off in many different directions. But also, when the laser beam strikes a pit’s “ridge”, it also strikes some of the flat surface of an adjacent land and a bit of the ridge’s bottom pit surface too! These several different surfaces create many different reflections of the laser beam. And, because a pit has a different elevation to a land, all the reflections from these various surfaces are out of time with one another and therefore they tend to cancel each other out. (Waves of light and sound will, in some cases, tend to cancel if they are out of time with each other, and such is specifically designed to occur in the playback of a CD - the player’s laser reflections are to cancel out when a “pit-ridge-land combination” is struck by the beam as opposed to reflections coming from just one flat surface such as a land only or a pit only.) The CD player’s light sensor can tell when it receives full “in-time” reflections coming back off a flat land or off the flat part of a pit. And, the sensor can also tell when it receives partial, “out-of-time”, broken up reflections when the laser beam strikes a pit-ridge-land combination (those areas in the track where a pit ends or a pit starts, divided by a land). This then gives two types of light reflections: 1) Full reflections from a land or a pit, and 2) Partial (mostly cancelled) reflections when the beam strikes a pit and ridge AND land all together. Note the number TWO. That is the Binary system once again! The CD player’s laser produces two types of light reflections and these are then used to precisely recreate the exact Binary number information that was on the original Plant Master! The light sensor receiving the reflections sends out electrical pulses when it detects full light reflections. However, when broken up partial reflections are received, the light sensor does not send out any electrical pulse. Therefore, the player’s light sensor provides “on” and “off” signals. Of course, that is how a computer works. In the field of computers, the binary number system is used. The binary system uses only two numbers (“1” and “0”) and those two numbers represent “on” and “off” of electrical pulses. A CD player is a computerised device, so, once it has recreated the exact binary information “contained” on the CD, it then quite easily converts that binary information to sound one can hear over loudspeakers or headphones.
c.d. CHANGER: A c.d. player that can store more than one c.d. at a time. Each c.d. can be accessed by the controls on the c.d. player. c.d. changers are common in cars as well as home audio. Some changers can hold many hundreds of cd’s while the more common type hold five. These are usually referred to as “mega-changers”. A c.d. changer with 3 to 5 discs is usually referred to as a “changer”. Many consumers like not having to get up to change to a different c.d.. If their favourite cd’s are already inserted into the changer, they just use their remote control to go to a different c.d..
c.d. COPY PROTECTION: See SCMS, COPY PROTECTION and COPY PROTECTION TYPES OF for full information.
CDDA: This is actually Sony and Philips’ official name for the compact disc. It stands for c.d. Digital Audio. Usually just called a “c.d.”.
c.d. DRIVE: A c.d. player for a computer.
CD-E: An abbreviation for c.d.-erasable. Another older name for CD-RW (ReWritable).
c.d. EXTRA: See ENHANCED c.d., ENHANCED MUSIC c.d.. It’s the same thing.
c.d. FRAME: A “c.d. Frame” is where information is actually stored on a compact disc. It is a grouping of all the information a c.d. player requires to play audio from a c.d.. There are various codes and control information, quite in addition to the digital music itself. A c.d. Frame is the smallest “grouping” of all such data the player reads and uses to operate. In order for a c.d. player to correctly read and play back the audio data stored on a c.d., there are several types of information the player requires from the disc, in addition to the music itself. A “c.d. Frame” is made up of the following data: The audio content itself, speed and stability information for the c.d. player, each song or track’s index numbers, running time, tracking numbers for royalty purposes, copy protection, text, graphics, pictures and error correction. The “c.d. Frame” is a basic building block of digital information contained on a compact disc, and is the smallest complete section of data that a c.d. player needs to play back its contents. All of the above data are included in the c.d. Frame. Because the frames pass by and are read by the c.d. player so quickly, one doesn’t hear the individual frames - much like you don’t see the individual picture frames when watching a movie.
Technical specifications follow... Each c.d. frame includes 27 bits of synchronisation information; 8 bits for PQ, text, graphic and picture sub-codes; 192 bits of audio and 64 error correction bits. Note that a DVD does not have “frames” as such. A DVD has files, much like a computer’s file system, and its audio and video information are in separate files from its “sub-code” information (sub-codes are called “metadata” on a DVD). The “frames” referred to on a DVD are the video frames, i.e. 30 frames per second.
c.d. ID’s: This is an abbreviation found in the SADiE digital audio computer manual and is used in reference to c.d. manufacturing. An Abbreviation for Compact Disc Identifications. A c.d. id. is a very brief digital signal that marks the beginning point of a track on a c.d.. A c.d. id. is part of the PQ Code (the code that contains the track numbers and length of time for individual tracks and the entire c.d.). PQ is defined as a separate entry. c.d. id’s mark the starting point of a song. For example, song number 1 on the disc is c.d. id. 1, song number 2 is c.d. id. 2 and so on. On a c.d. player, when you use its double arrows (the “skip ahead” or “skip back” buttons), you are telling the player to find the c.d. ID at the beginning of the track you wish to hear.
CD-i or CD-i READY: Compact Disc Interactive was developed by Philips and Sony. It is a c.d. that has the ability to allow the user to participate in its recorded programme. A cd-i ready disc is able to do interactive functions with certain types of c.d. players which have the interactive function built in as a special feature. It will not allow user interaction on a normal music c.d. player.
c.d.: The 16 Bit, 44.1 Sampling Rate c.d. for music and all other types of audio programme - the conventional c.d.. (See c.d. TYPES OF for full listing of current names and-or types of cd’s and what they are.)
c.d. PLANT MASTER: See PLANT MASTER.
c.d. PLAYER: An audio component that plays one c.d.. (Compare c.d. TRANSPORT and c.d. CHANGER.)
c.d. PLUS: See Enhanced c.d.. It’s the same thing.
CD-R (c.d. RECORDABLE): C.d. recordable technology is used for the production of “one-off” cd’s. (When one makes only one copy of a c.d., that one copy is said to be a “one-off” - as opposed to mass-produced cd’s done at a manufacturing plant.) Conventional c.d. players will not record onto a c.d., as they are not designed and built to do so. However, c.d. machines that will record are commercially available. CD-R recorders will not record onto a conventional c.d., they will record only onto “c.d. recordable” discs. CD-R discs have a different composition than a conventional c.d., but once they are recorded they will play on most conventional c.d. players - including the c.d. players built into a computer. One way the CD-R is used at Gold is to record a lecture mix in order to judge how it will sound if released on compact disc. Additionally, a CD-R can be used to make a cd-rom. For example, a tape transcript can be recorded onto a CD-R from a computer file, at which point the CD-R becomes a cd-rom containing the transcript. (important note: There are different types of recordable cd’s and not all will play in every type of c.d. player. See “c.d., TYPES OF” for a full listing of all names and types of cd’s including those which are recordable and their differences.)
CD-RDx: The cd-rom read-only data exchange standard, developed by the CIA (Central Intelligence Agency), aimed to allow CD-ROMs to be recorded and their data to be input into computers that met certain standards. Not common in audiovisual applications.
CD-ROM: An abbreviation for Compact Disc Read-Only Memory. Read-only memory means that the data stored on the disc can be displayed only, not changed or rerecorded. CD-ROM’s contain such things as tape transcripts, illustrated encyclopaedias and dictionaries which one reads from a computer’s display screen. Once a CD-ROM has been recorded, the data on the disc cannot be altered. (One could load the data into a computer and change it there, but not on the CD-ROM itself.) A specialised use of the CD-ROM data format is in the production masters run by the Gauss Line Digital Bin for cassette mass production. The CD-ROM data needed to produce cassettes is recorded (“burned”) onto a recordable CD (CD-R) in audio. (Once the CD-ROM data is burned onto the CD-R, it then becomes a “read-only” disc.) Note that the term CD-ROM is used to refer to two different things. One is the type or format of data stored on a compact disc and the other is the disc itself. Any CD that can’t be recorded onto after it is originally made might be called a CD-ROM, including audio CD’s such as those containing LRH lectures and music releases, but such are more commonly - and correctly - simply called “CD’s”.
CD-ROM DRIVE: The mechanism in a computer which plays and reads the data from a CD ROM.
CD-ROM XA: The CD-ROM Extended Architecture disc was developed by Sony, Philips and Microsoft. It is used for data, graphics and compressed audio and video. The CD-ROM XA makes it possible to read and display jointly text, audio and graphics files. It’s called “extended architecture” because the CD-ROM format has its basic design extended to allow the CD-ROM to play audio and graphics as well as text. The CD-ROM XA can be read by a computer with a CD-ROM XA drive.
CD-ROM TOWER: This is a configuration of CD-ROM drives in one box, known as a tower. CD-ROM towers are usually implemented in networks, usually with an appropriate CD-ROM server. They work well in busy multi-user environments because all the drives in the tower are accessible at all times.
CD-RPW: A recordable CD (CD-R) that has a Printable White surface, on which one can write with a marker.
CD-RW (REWRITEABLE): This type of recordable CD can be recorded onto and then erased and re-recorded onto many times. It requires its own special RW type recorder BUT will play on any player. A CD-RW will not record in a CD-R recorder. They are more used for computer data and lower quality music recording where the consumer wishes to rerecord favourite songs, etc.
CD SINGLES (music): 1) Note that there are CD singles available which have only one or two songs on them. These usually sell for about $4.00. This type of “CD Single” does play in a normal CD player. 2) Since 1991 the 3 inch (8cm) “CD Single” has been popular in Japan. Can play music and data. Is not for play on a normal music CD player. Can play on Sony’s “Data Discman”.
CD SUB-CODES: There are several types of digital information recorded onto a CD in addition to its primary audio programme (music, lecture, etc.). Some of this other digital data are “instructions”, without which a CD player would not be able to locate a particular song or portion of a lecture when “Play” or its “Track Skip” buttons are pressed, nor would the player display a track’s number or time length. This type of code information on the CD is called “PQ Codes.” (PQ is defined as a separate entry.) There can be other types of additional digital information (sub-codes) as well. For example, text files and graphics can be put on the disc and these can be seen when the disc is played in a computer. There can be up to eight different sub-codes on a CD, all in addition to the music or lecture audio information. A CD has a long continuous “track” (path) of pits and lands which are read by the CD player’s laser. These pits and lands contain the digital information for the audio information on the disc. The sub-code data is actually right on the same track, it’s just different pits, ridges and lands than the actual audio information. (The CD player’s laser pick-up head reads the sub-code pits, ridges and lands (data bits) right along with the sound signal. The player’s electronics are set up to detect which bits are audio information and which are sub-code information.) There are eight sub-code bits per CD Frame. (CD FRAME is defined as a separate entry.) These bits are P, Q, R, S, T, U, V and W. The P and Q bits are for the PQ codes. These bits start at “P” because the first bits (A - O) are for the audio data. (Bits R through W are for text, graphics and pictures.)
CD TEXT: There is information on a Compact Disc that gives data in text form about the music that it contains. The name of the artist, song, and other information can be displayed on TV or projection screens if the CD is played over a DVD player. Many home components can do this and some can output the text for display on a TV or projection screen. Some car audio components will read this information as well and show it in the display windows of that equipment in the dash of the vehicle.
CD TRANSPORT: A unit that looks like a CD player but no analogue sound signal comes out of it. It is really only a unit that spins the CD and reads the information on the CD. The unit is for sending only the digital signal of the CD to yet another unit that actually processes the CD’s digital signal and creates sound. A CD transport is always used with this other unit. The other unit is called a Digital to Analogue Converter. A CD transport is an audio term. A “CD Drive” is a computer term - it is the mechanism that plays cd’s in a computer.
CD types of: There are different types of CD’s made that are commonly heard about in the audiovisual industry.
NAMES AND TYPES OF CD’s
16 Bit, 44.1kHz sampling rate CD for music and all other types of audio programme - the conventional CD.
Consumers can make their own CD recordings using MP3, a digital compression format, to get tons of songs onto one CD. The consumer can record music from his own CD library or download music from the Internet and put it all onto an MP3 CD that he makes himself using a relatively inexpensive MP3 CD recorder which can be in his computer, or a small stand-alone device.
SACD - Super Audio CD (Sony)
Super Audio Compact Disc. SACD is a new, higher resolution type of music disc and player. It was developed by Sony and Philips. SACD actually uses a DVD type disc, but its information is recorded with a proprietary digital method developed by Sony and Philips.
HDCD (High Definition Compatible Digital) disc
A specific trademark for a type of “High Definition” music compact disc. A digital music production method from the Pacific Microsonics company. HDCD’s are often sold through music stores. The discs will play in CD players, but to hear “HDCD”, the CD player must have a special chip inside made by Pacific Microsonics. When the player has such, it will be labelled “HDCD”.
Surround CD (music)
16 Bit, 44.1kHz sampling rate CD for music in surround sound. Is meant to be played over DTS or Dolby circuitry in home consumer electronics. This format of CD has been most heavily pushed by DTS with over 200 titles produced.
mini CD (music)
A smaller version of the normal music CD holding less music but at same 16 Bit, 44.1kHz sampling rate. Will play in most all normal players.
card CD (music, data)
A small CD, intended for use as a type of “business card”. They are meant for 2 - 3 minute audio, data marketing presentations and will play in any normal CD player BUT for those types of CD players, common in cars, where there is a narrow slot in which the CD is inserted. The small card CD is not large enough to be grabbed by this type of player’s mechanism for insert and eject. The cards are produced as a read only memory (ROM) CD at normal CD rates.
CD Singles (music)
There are CD singles available that have only one or two songs on them. These usually sell for about $4.00. Also, in Japan, since 1991, the 8 cm “CD Single” has been popular for playing music and data but are not for play on a conventional CD player; they can play on Sony’s “Data Discman”.
CD-V (video) or VCD
It is possible to put video information onto a normal CD. CD-V can hold approximately 5 - 6 minutes of full motion video and about 20 minutes of audio tracks. Requires a special player or CD-V drive. Note: This type of CD is more common overseas where special players are sold for such. Not to be confused with a “Video CD”, which is a common name for CD’s that contain video games, especially in the Far East.
Super Video CD. Same as a CD-V, but has the higher quality Super VHS picture, which requires more digital information.
CDDA or CD-DA
Sony and Philips designed the original CD and they called it the Compact Disc Digital Audio. These two companies still often refer to the standard CD as the “CDDA” in their promo and manuals.
A CD that has the ability to allow the user to participate in its recorded programme. Requires some special electronics that allow user to access the CD’s contents. Will not allow user interaction on a standard CD player.
Video CD (games)
Common in the Far East. This type of CD holds video games. Can be played on computers. Will not play on a standard CD player.
Audio CD-R (Recordable)
This type of CD is specifically meant to record high quality audio (music, etc.) and can only be recorded onto once. Can not be erased - was earlier referred to as a “WORM” CD, meaning (Write Once Read Many). Will play in most CD players. Will play on all computers with a CD or DVD drive. Makes very high quality copies. Some studios use CD-R for final copies. Excellent for archival recordings. Some CD duplication plants will accept a CD-R master providing it is made to their specifications.
data CD-R (Recordable)
The same as an audio CD-R as listed above but sold as intended to store computer data information.
CD-ROM (Read Only Memory)
A CD-ROM is essentially just like a normal music CD in that it is purchased with its content already stored. It can only be read from, neither recorded to nor erased. However, the CD-ROM is actually the type of CD used by computers as it contains data information (text and graphics). It also has additional error detection and correction specifically for computers as opposed to CD players.
CD-ROM XA (Read Only Memory Extended Architecture)
Developed by Sony, Philips and Microsoft. Used for data, graphics and compressed audio and video. Makes it possible to read and display jointly text, audio and graphics files. It’s called “extended architecture” because the CD-ROM format has its basic design extended to allow the CD-ROM to play audio and graphics as well as text. The CD-ROM XA can be read by a computer with a CD-ROM XA drive.
A recordable CD (CD-R) that has a Printable White surface, on which one can write with a marker. (More data at CD-R).
This type of recordable CD can be recorded onto and then erased and re-recorded onto many times. Requires its own special RW type recorder BUT will play on any player. Will not record in a CD-R recorder. More used for computer data and lower quality music recording where the consumer wishes to rerecord favourite songs, etc.
ENHANCED MUSIC CD, CD-PLUS, CD-EXTRA
A compact disc format that allows the combining of audio recordings and computer data on the same disc, without the possibility of audio equipment becoming damaged by attempting to play the computer data sections. The CD-Plus can have an audio programme, plus text, graphics and still pictures.
Put out by Kodak for the storage of photographs. Read by a computer.
CD-RDx (Read only Data Exchange)
The CD-ROM Read-Only Data Exchange standard, developed by the CIA, aimed to allow CD-ROM’s to be recorded and their data to be input into computers that met certain standards. Not common in audiovisual applications.
MMCD - MULTIMEDIA CD
Said of CD’s that include text, sound, and motion video for informational, educational, and entertainment products which are then played over personal computers. This is an actual compact disc format whose use has also helped define the new term of “infotainment”. Includes the newer “interactive CD’s”, which allow consumers to involve themselves in the programming of the CD. These are played on personal computers having a CD or DVD Drive.
MULTISESSION or MULTISESSION DISC
Usually a recordable CD must be recorded to all at one time, meaning you record to the disc once and then that’s it. There may be room for more information to be recorded, but once you stop the initial recording process, the disc will not accept any further information. However, there are “multisession discs.” These allow a recording to be made to a disc during one “session” (one finite period of time) and then additional recordings to be made in later sessions. Some types of recordable compact discs can require more than one recording “session” to create their contents. For example, a CD that has music plus graphics, text and still photos usually has these different types of data recorded during separate sessions. The music may be recorded first, and in subsequent sessions the text, graphics and pictures are added onto the recordable CD.
CD-V: Stands for CD-Video. It is possible to put video information onto a normal CD. CD-V can hold approximately 5 - 6 minutes of full motion video and about 20 minutes of audio tracks. It requires a special player or CD-V drive for your computer. Not to be confused with a “Video CD”, which is what video games are commonly played on in the Far East.
CD-WO: An abbreviation for Compact Disc Write Once. This is an older name for CD-R (CD Recordable). The term “CD-WO” is not used much anymore.
CEA: An abbreviation for Consumer Electronics Association. An association involved with forwarding of consumer electronics industry interests and cooperation amongst designers, manufacturers, distributors and retailers. They host the Consumer Electronics Convention each year in January in Las Vegas.
CEDAR: Acronym for Computer Enhanced Digital Audio Restoration. CEDAR is a company in England that originally designed and built digital audio equipment to help improve the sound quality of very old voice recordings. Some are on old phonograph records and the sound has many snaps and pops when played. CEDAR developed computerised equipment to get rid of the pops. Their equipment can now do many additional audio restoration functions. It is considered the highest quality digital restoration equipment available. The Lecture Mix Team at Gold have worked quite closely with the CEDAR company and developed considerable techniques and skills in applying the CEDAR technology. Together with advanced Clearsound equipment and procedures, CEDAR restoration has enabled far more LRH lectures to be released - lectures which, just a few years ago, sounded so poor due to the state of their original recording, that their release to public was literally impossible.
CELESTIAL JUKEBOX, HEAVENLY JUKEBOX: The coined terms for the vast library of music available on the Internet.
CELL: Most modern musicians and composers use computers. They assemble songs by recording into the computer bits of music. Some may be as short as a one second strum on a guitar. Others can be longer. The “cell” is a brief bit of music loaded into the computer. This is then looped (made to repeat). There can be a “key cell”, which is the bit that becomes the nucleus for the song - meaning the main melody and basic stylistic pattern. “Warping” of cells is done too. By this is meant, a cell can, by way of computer manipulation, be lengthened, shifted as to pitch, parts of it stretched out in time, etc. Cells can be built up one upon another by layering the bits of music on top of each other. Usually a rhythmic bed (fundamental layer) of loops is created for the song with more cells added on top of the looped rhythmic bed. A great many music releases are actually prepared this way - full songs are put together in this manner. Many different sounds and patterns of rhythm are loaded into the computer. These are called “cells”.
CELLO AUDIO PALETTE: This is a brand name of a very high-quality equaliser sometimes referred to as “The Cello”. As an equaliser it has selective volume controls for the different frequencies of sound from low bass to the highest treble. The word “palette” is descriptive of its use as a tool for a Mixer’s artistic application and use of the equaliser.
CELL PHONE: Short for cellular telephone. A mobile wireless telephone service that uses low-powered radio transmitters (antennas) set up to cover a distinct and limited geographical area. When you are travelling in a car using a cell phone you are actually entering and leaving many different “cells” (specific areas covered by different individual antennas). The cell system “searches” for your phone in every cell, locates it, and then, as you travel along talking on the phone, the system then switches (cell to cell) to follow and keep providing phone service. In actual fact, a cell phone is continually putting out a small electronic signal to the nearest cell antenna - that’s what is happening when you see that small light continually blinking on a cell phone indicating that you have good or poor reception. Your phone is “talking” to the nearest antenna. In this way, the cell system of antennas knows where you are should you receive a call and you know that you have good reception (if the indicator light on your phone says so). So, even though you are not speaking over your phone, the phone itself is always on and always searching for and “talking to” the nearest cellular phone system antenna. When you receive a call, it can find your phone almost instantly. Cell telephones work using radio waves. They are really two-way handheld radios of a sort. Your phone uses an assigned radio wave frequency. That is your “phone number”. When someone calls your number, the cell system puts out the call on your assigned frequency so you can receive it. The cellular phone companies have their cell antennas set up and working so that one antenna takes over before another is out of range as you travel and move about within the overall area in which your cell phone service is provided. Thus there is a seamless network created composed of adjacent and interconnected “cells” (which really means individual antennas and their individual coverage areas to provide service coverage to your individual phone).
CELLULOSE, CELLULOSE ACETATE: See FILM.
CENTRE (the): 1) The centre seating position - the prime, best seat in front of a loudspeaker system. 2) The centre loudspeaker in a surround sound audio system. 3) The centre channel, the one with the audio signal for the centre loudspeaker in a surround sound loudspeaker system.
CENTRAL DRIVING POSITION: Said in regards to audio systems installed in cars and other vehicles. These systems are adjusted so the volumes of the loudspeakers within the car give an even balance of sound for the driver’s position. This is then referred to as the “central driving position”.
CENTRE CHANNEL, CENTRE CHANNEL SPEAKER: In Dolby and other surround sound systems, the signal sent to the centre speaker is called the “centre channel”. (Sometimes the word “channel” is used synonymously with “loudspeaker”.) The centre channel speaker in commercial theatres is always centrally located behind the screen. The centre channel is primarily for dialogue, so the effect is that their speaking voices come directly from their mouths - from the centre of the screen. In home theatres, the centre channel speaker is normally placed directly above or below the TV screen. This can also be achieved by using two centre channel loudspeakers - one above and one below the screen.
CENTRE CHANNEL TIME CODE: Also known as centre track code. A recording of SMPTE time code between the two stereo audio channels on a two track tape recorder so that the tape can be synchronised to other machines.
CENTRE FREQUENCY: The frequency of the audio signal that is boosted or attenuated most by an equaliser.
CENTRE SPEAKER: See CENTRE CHANNEL.
CENTRAL PROCESSING UNIT (CPU): See CPU.
CETEC-GAUSS: This is the name of a company that manufactures cassette high speed copy equipment. Note: The company is now owned by a Swedish corporation called M2, a manufacturer of digital equipment. Cetec-Gauss is now called M2 Gauss.
CGI: An abbreviation for computer generated image.
CG OPERATOR: “CG” stands for Computer Graphics. CG machines are used to create video and television special effects and are common in broadcast facilities (including trucks). CG mostly refers to the types of machines used to create titles on screen. A CG Operator is the person operating such a device.
CHAIN: The group of equipment that a Mixer will have patched together in series to process an audio programme to his liking. Several pieces of equipment may sometimes be used together. They are called a “chain” or “the mix chain”. Also referred to as one’s “line”.
CHAMBER (echo chamber): See ECHO CHAMBER.
CHANGEOVER DOT: See CHANGEOVER PROJECTION.
CHANGEOVER PROJECTION: When 35mm feature films are played using two film projectors, one must “change over” between the two projectors as each reel of film ends. More modernly, in virtually all commercial movie theatres, all reels of film are edited together on a huge platter to form one continuous strip of film, which is then run through one projector. Screening rooms are sometimes equipped with two projectors with each reel of the film kept separate, playing one projector then the other throughout a film’s playing. The projectionist will manually start the next projector when he sees “changeover” dots in the upper right corner of the screen. These are the black dots that appear in the corner of the screen. They give several seconds warning to the projectionist that the other projector will very soon need to be started and the presently running projector stopped.
CHANNEL, CHANNELS: A single path or paths on which an audio signal travels or can travel through a device from an input to an output. A channel is a complete sound path through audio electronic equipment. Mixboards used for mixing music, films, etc. have channels. This is differentiated from TRACK, which generally refers to individual tracks (instrument or vocal recordings) on a single recording tape. Some tapes can hold up to 24 different individual recordings - up to 24 different “tracks”. The sound for each track is sent by a channel. One can have 24 channels on a mixboard, and through those, record or process 24 individual tracks. Mixboards have channels and tape recorders have channels. Recording tape has tracks. A song or music piece is said to have “tracks” (of different instruments or singers). Sometimes the two words are used interchangeably. A single-channel is called “mono”. Stereo has two channels - left (A) and right (B). A surround sound mix or audio loudspeaker system may have 4, 5, 6, 7, 8 or more channels. In a surround system, one channel goes with one (or one set) of loudspeakers.
CHANNEL SURFING: See SURF.
CHARACTER GENERATOR: A computer used to generate text and some types of graphics for video titles.
CHARGE: An accumulation of electricity. Charge can be positive or negative. A negative charge means there is an excess of electrons (negatively charged particles). A positive charge means there is a scarcity of electrons. When a wire or conductor is connected between a negatively charged body and one with a positive charge, the excess electrons from the negatively charged body vibrate back and forth along the conductor - toward the positive body. The resulting motion of electrons is called electrical current.
CHASSIS GROUND: The conducting connection from earth (ground) to the chassis or frame of a component. This differs from electrical ground which is the third wire (connected to the bottom prong of the plug) in a power cord in an electrical circuit. Both are connected to earth but via different paths.
CHEAP SAMPLE: A poor sounding electronic attempt to synthesise the sound of a real instrument. Said of any electronically created sound used in a mix that sounds unauthentic and not up to the quality standards of top of the line music productions.
CHECKPRINT: A “checkprint” is a film which is produced by the Film Lab and submitted to QC for approval on the final visual look and quality of the film. It is used to judge whether or not colour corrections done to the film are a pass. Checkprints are made at different stages leading up to the production of final Release Prints for orgs. There is a final checkprint. It is another name for the final, approved, Answer Print. This must receive final QC approval.
TYPES OF CHECKPRINTS
“Lab Checkprints” are unsubmitted initial test prints, not the “final Checkprint”, always made from the initial internegative (IN) only. Done to establish correct colour settings for running final release copies of the film. A submittable lab Checkprint becomes the “rough Checkprint” and is sent to final QC for approval.
The “Rough Checkprint” is a test print submitted by the Film Lab Dir to final QC. It is always made from the initial IN only. Once approved by final QC, the “Rough Checkprint” is named the Final Checkprint, also called the Final Answer Print.
CORRECTED ROUGH “CHECKPRINT”
The Corrected Rough “Checkprint” contains any corrections required by QC, still using the initial IN, never the original negs. Once approved by final QC, the “Rough Checkprint” is named the Final Checkprint, also called the Final Answer Print.
This is the final checkprint approved by final QC. It is also called the Final Answer Print. Only when this is approved by final QC, may the film lab proceed to produce prints for release to orgs.
CHIP: A slang term meaning a microchip - a small piece of silicon holding a complex electronic circuit. Also sometimes called an integrated circuit.
CHORALISER: In one of our echo chambers used by the music studios, exists a “choraliser”. It is called a choraliser because it gives a chorus-like effect to music sounds being mixed. The choraliser consists of two microphones, each attached to one end of a long pole. The pole (and microphones) are spun around and up and down at the same time. As the microphones spin, they come closer and then further away from the walls of the echo chamber. There are also loudspeakers inside the echo chamber and the microphones are drawn closer and further away from them too as they are spun ‘round and ‘round. This motion, as well as the many echoes being picked up by the microphones is heard as a very unique quality of reverberation. It works on the Doppler principle. (Doppler was an engineer who discovered that if a source of sound is moving in relationship to the listener, it will be heard to change in pitch. You have heard this phenomenon when you heard a police car or fire engine with their sirens on approaching and passing your location. The sound actually goes higher in pitch as it approaches you and lower in pitch once it passes - the faster they are moving, the more pronounced the effect.) Because the microphones of the choraliser are moving closer and further away from the sound reflecting off the chamber walls and coming from the chamber’s speakers, the sounds are actually slightly changing in pitch (frequency). This gives a very rich sound and can actually sound like many different instruments of the same type are playing “a chorus” of instruments. We are the only studio in the world with such a choraliser. It was originally conceived by a very skilled audio engineer named Paul Veneklausen. His original design was refined here and then installed by our Estates and Audio staff. Its speed of rotation is entirely adjustable from inside the LRH music studio by way of a controller at the mix board. The choraliser is used on many of our music productions.
CHORD: Two or more musical notes played at the same time.
CHORUS: 1) The part of the song that is repeated and has the same music and lyrics each time. 2) A musical singing group that has many singers. 3) A delay effect - a delay is a signal that comes from a source and is then delayed by a tape machine or a piece of electronic mixing gear and can be mixed with the original signal to make it sound fuller, create echo effects, etc. - which simulates a chorus. 4) A similar effect created in some synthesisers and by some guitarists by detuning (reducing the pitch of, slightly) and mixing it with the signal that has regular tuning and with a slight delay.
CHORUS PARTS: The singers in a song or piece of music who are singing chorus-like parts which add size and support to the music.
CHROMA, CHROMINANCE: Purity of a colour, determined by its degree of freedom from white or grey; the hue and saturation of a picture of an object as differentiated from the brightness of that object. “Chroma” is short for chrominance. The word “chroma” means colour. It is the colour part of a signal, relating to the hue and saturation but not to the brightness or luminance of the signal. Thus, black, grey and white have no chroma, but any colour video signal has both chroma and luminance (brightness).
CHROME TAPE: Cassette tapes are manufactured with various different particles used as their magnetic material. “Chrome tape” is one of the higher quality cassette tapes and is sometimes used for commercial music releases. The magnetic particles used in chrome cassette tape are actually an oxide of chrome (just like ferric tape is an oxide of iron - rust). Chrome tape is chromium oxide.
CHTML: Short for Compact Hypertext Mark-up Language. This is the version of HTML used for small handheld Personal Digital Assistants. (HTML is defined as a separate entry.)
CHYRON: Short for Chyron Corporation. A major manufacturer (based in Melville, NY) of electronic image and character generators and TV graphic systems, particularly those used by many TV stations and producers for lettering and graphics. The systems are so common that the company name sometimes is used generically or as a verb (to chyron an identification).
CineAlta: The Sony-Panavision product line of video cameras, processing and playback equipment that operate at 24 fps (Frames Per Second) in progressive scanning mode at High-Definition image resolution.
CINEMA CONNEXION: The brand name of a method for film showings used in theatres. No film is used. It is entirely digital.
CINEMA EQ: (Cinema Equalisation.) This is a term that describes a feature on some home theatre audio equipment that dulls (takes some of the high treble frequencies away) a film soundtrack when it is played in the home theatre. The reason for this feature is that often the film soundtracks were mixed with boosted (raised in volume) high frequencies to sound okay in movie theatres - because theatres intentionally remove high frequencies from their audio loudspeakers. (Why this is done for theatre loudspeakers is fully covered under the glossary entry “X CURVE”.) If the film is then played at home and sounds too bright (too much high frequencies), then the cinema EQ feature can be selected on the consumer’s surround sound receiver or processor.
CINEMA DSP: (Cinema Digital Signal Processing) A Yamaha audio electronics feature designed to enhance Dolby and DTS surround sound playback for films.
CINEMA MODE: A DVD video player feature which compensates for the high-contrast scenes in a film. This is an issue because conventional videos and video equipment do not have the capability of film to show gradations of contrast (dark blacks, greys, etc.). DVD’s use video for the source of their pictures. “Cinema Mode” brings out the darker parts of a movie so they can be seen more easily on video. It is available on some Panasonic DVD players.
CINEMA PRACTICE: How it is done for the cinema - the “practice” or “practices” (techniques) used in creating a film or its surround soundtrack.
CINEMA PRO LOGIC: This is a version of the original Dolby Pro Logic that is found on home consumer preamps made by a home audio electronics manufacturer named Adcom. Per the technical department at Adcom, Cinema Pro Logic is just Adcom’s version of Pro Logic and it is not found on equipment from other manufacturers. Adcom claims that it is an “enhanced” version of Dolby Pro Logic 4.1 surround, but it is not a version of the new Dolby Pro Logic II nor is it THX certified.
CINEMASCOPE: This was a trade name, spelled “CinemaScope”, of Twentieth Century Fox film studios. It was a forerunner to what is now simply called “widescreen”, which is commonly used now for displaying Hollywood feature films.
CINEMA WIDE: See this heading under ASPECT RATIO for definition.
CINE MIX LINE: This line is in Studio II - up the hill on the north side of the property. It is where all the individual parts of a film’s soundtrack are assembled and mixed into the final audio product. Many sounds are created and added to complete the soundtrack right in Studio II before mixing begins. The Cine Mix Line is specifically where the mixing itself is done. Another room (and other production line) is used for recording the sound effects.
CINERAMA: In the late 60’s some movie theatres were built having extremely large screens. Their name was “CINERAMA”. Cinerama films were produced using three 35 millimetre projectors for each film scene. All three projectors combined to display a very wide image and they projected concurrently on a huge screen. The Cinerama system in a theatre is comprised of three 35 millimetre projectors which run concurrently in sync with each other. The first Cinerama film was “How The West Was Won”. Stanley Kubrick’s “2001: A Space Odyssey” was an early Cinerama film. The system itself is no longer in use, but some of the theatres are still in operation playing normal film presentations, such as the “Cinerama Dome” on Sunset Blvd in Hollywood California.
CIPHERTEXT: A message or information sent via computer after it has been encrypted for security. When decrypted, it can be read once again as plaintext.
CIRC: An abbreviation for Cross-Interleaved Reed-Solomon Code. A technology used in compact discs for error detection and correction.
CIRCLED TAKES: When keeping admin for a sound recording and-or film or video shot, a log is kept for each shot that includes the shot number and each take of that shot, in addition to other vital data. Separate logs are kept by the Sound Recordist, the Assistant Cameraman, Script Supervisor and others. When a take is a “cut and print”, that take’s number is circled on the logs. This provides an at-a-glance reference for locating the takes that are “cut and prints”.
1) One complete path of electric current. For current to continually flow there must be a path for the electrons to travel. That path is the “circuit.” The derivation of the word circuit is “to go” or “to go around.” Electricity in a circuit actually flows (travels) from one point and then circles (goes around) back to the originating source. For example, electricity flows out from a battery, to a flashlight bulb, and then back to the battery. That is a complete circuit. It is why there are two wires in any cord you plug into a wall socket - the electricity has to come out of the wall and flow back.
2) Is also used to describe any particular section or part of an electronics device that does a specific function in the context of the entire electronic workings of the unit. “The record circuit of the tape recorder was calibrated to make a perfect recording.”
CIRCUIT BREAKER: A protective device, in the form of a relay (switch), which breaks the electrical flow in a circuit in case of an overload. Similar to a fuse.
CIRCUIT BOARD, PRINTED CIRCUIT BOARD: In the old days of electronics, the many small parts inside an electronics device were hooked together into a circuit using only short pieces of wire. Later, boards were developed upon which electronic parts were mounted. These boards have “traces” (thin runs of copper) that route the electrical flow in the circuit, instead of wire. Modern electronics uses circuit boards extensively in building any piece of electronic equipment. Wire is still used, but usually to connect circuit boards to other boards, or to the various connectors to get in and out of the unit as well as to run electrical power (from the wall) to the circuit boards. Printed circuit boards are created using a process similar to the developing (printing) process used to develop a photo (thus the term printed).
CIRCUITS: The many various electrical flow paths in any electronics device. Look inside and see all the wires and paths on circuit boards. Those are the “circuits”.
CLADDING: Special material used to line or cover an optical fibre to reflect and confine the light waves to its core.
CLAPPER: When shooting a movie, it is vital that an exact point in time is marked for each shot, both on the sound recording and on the film. This makes it possible to rapidly identify the shot later on and to marry up the sound and pictures so they run in synch with each other. At the very start of each shot, when the film camera and the sound recorder are both running, a “clapper” is used. It is a handheld erasable chalk or marker board with a “clapper” on top, which can be sharply swung closed creating a loud “clap” against the body of the board. It marks the start of a cine shot. Upon the board is written all pertinent information about the shot for identification. The “clap” sound was recorded and the “clap” of the clapper snapping shut is visible on the film. By marrying the two together so they are heard and seen at the exact same time, one knows the audio is now in synch properly with the pictures. The actors can talk, and the sound will be heard in perfect time with the movement of their lips.
CLAPPERBOY, CLAPPERGIRL: The person whose hat it is to operate a clapper. (See CLAPPER.)
CLEAN POWER, DIRTY POWER: Common electrical power coming directly out of distribution points (“mains” - like circuit-breakers and wall outlets) may have voltage fluctuations, interference and distortions. Electricity with these faults is referred to as “dirty power.” Dirty power can be caused by such things as the power company not sending a steady current, an air conditioner or refrigerator turning on creating a drop in power, or even local radio stations’ broadcast interference. The term “clean power” describes a smooth flow of electricity that has very stable voltage and is free of distortion and interference. Audiovisual equipment operates at its optimum with clean power and therefore all A.V. production lines are provided such. The dirty power is processed by a device called a “line conditioner,” which has circuits to monitor electrical current, correct most voltage fluctuations and remove nearly all types of interference.
CLEARCOM: The name of a company that makes intercom systems so professional audio personnel can communicate one to another during a broadcast and-or event.
CLEARSOUND: The technology of Clearsound was developed under LRH’s guidance. Specifically, the tech. came about as a result of a project done to upgrade the audio reproduction quality of LRH lectures. It was predicted by LRH that if the original recording machines used for the lectures were located, and if their exact recording characteristics were duplicated, there would be a marked increase in the quality of the reproduction of lectures. After an extensive search, the original machines were located and fully tested. Charts were drawn up as to the exact characteristics of the recorders - how each responded to bass, middle and high frequencies. Then, these response charts were used to set up the playback machines on the Lecture Mixing Lines. LRH’s prediction held true. The clarity of the sound was improved remarkably by duplicating the characteristics of the original recorders. There are a lot of technical details concerning Clearsound which are fully documented, but this is its basic genus. The Clearsound concept was expanded to encompass a quality standard for Gold’s sound lines and audio products. “CLEARSOUND” is the service mark Gold uses to denote extremely high quality for all audio products produced using LRH sound technology. Products are authorised to bear the CLEARSOUND logo if they are: a) produced on equipment which meets all LRH specifications, b) if the equipment is part of an authorised and approved production line, c) if the procedures used to produce the audio product were in full accord with technologies for sound recording, mixing, transferring and copying as written by LRH exactly and d) if the product passed QC per authorised routing form. The CLEARSOUND logo is also sometimes placed on equipment that is designed at Gold to be part of an A.V. system for our production lines or for an org A.V. presentation line.
CLEARSOUND RIG, CLEARSOUND RECORDING RIG, CLEARSOUND LOCATION RECORDING LINE: This is a very special system of tape recorders, both digital and analogue, in custom travel cases, which is taken by the Shoot Crew to record a film’s dialog shots done on location. It was entirely custom made here at Gold.
CLEARTEXT: A non-scrambled digital television signal which can be received by any digital television set that is connected to a cable TV provider or tuned in to receive a digital satellite or terrestrial television channel. It is said to be “cleartext” because its digital information is readily available to anyone having a digital TV receiver and it is clear (not protection coded and therefore not blocked from free access and viewing). Not all digital TV programmes are encrypted for copy protection and reception restriction purposes. Those which are not are said to be “cleartext”. Examples of cleartext digital TV broadcasts include local TV stations’ broadcasts, advertisements and most news programmes. An example of one that may not be cleartext is a movie channel which shows premiere Hollywood films. The computer version of “cleartext” is called “plaintext”.
CLEAR THE BOARD: 1) To get ready to do a new mix by returning a mixboard to all its normal settings and un-patching any equipment so one can start fresh. 2) To entirely restart a mix from scratch. “We decided to just clear the board and start over.”
CLICK: 1) On a kick drum, the sound of the sharp hit of the beater (the part of the foot pedal that hits the drum) when it strikes the drumhead (skin). 2) An unwanted sharp, brief, snapping noise heard on some audio programmes, especially on damaged vinyl records.
CLICK TRACK: A recorded track, using the sound of a metronome or similar device, which is used by the musicians in order to keep time with the piece as they record their instrument or singing parts. It is generally fed into a pair of headphones which the performer listens to, at low volume, in addition to a guide track or whatever recordings for the song have already been done.
CLINICAL: In audio, too clean or analytical. Emphasised high-frequency response. Has no warmth and not enjoyable as natural qualities are not present in the sound. Sounds like it was produced electronically in such a way that it does not sound natural. Would only exist in a “clinical laboratory” not in real life.
CLIP: 1) See CLIPPING. 2) This is a term used in the SADiE digital audio computer manual. When editing the soundtrack for an audio product using the SADiE system, any part of that track can have its own name - its own designation to distinguish it from other parts of the soundtrack. A clip is not actually a separate audio recording, but a set of instructions to replay a track between the in and out points of an edit. It is called a “clip” because of its similarity to a razor bladed (“clipped”) section of audio tape. A computerised “cut” is done at an exact point in the programme and the edited section is called a clip.
CLIP LIGHT INDICATOR: Any equipment used to record, mix or play back sound has limits as to how much volume it can handle without distorting. This is the case for both analogue and digital audio gear. “Clipping” is a form of distortion where the peaks in volume of an audio signal get chopped (clipped) off. This occurs when there is more volume running through a piece of equipment than its circuits can handle. The sound that digital equipment makes when it “clips” is an unpleasant thumping or clicking noise. Analogue gear generally makes a fuzzy distorted sound when clipping is present. A “clip light indicator” is a small light mounted on the front panel of a piece of audio equipment that flickers to alert the engineer that clipping is occurring. They can also be mounted on or near a meter which registers changes in volume. Anyone using audiovisual equipment must know how much volume can be put through a piece of equipment to ensure that his recording or mix is free of distortion. A clip light indicator is one of the tools he uses to judge this.
CLIPBOX SERVER: A type of video editing and broadcasting equipment which can store shot bits of video footage (a “clip”) for instant playback. No tape is involved so there is no rewind time and the clip will play the instant the “play” button is pressed.
CLIPPING, CLIP: “Clipping” is a form of distortion where the peaks in volume of an audio signal get chopped (clipped) off. This occurs when there is more volume running through a piece of equipment than its circuits can handle. The sound that digital equipment makes when it “clips” is an unpleasant thumping or clicking noise. Analogue gear generally makes a fuzzy distorted sound when clipping is present.
CLIPSTORE: This is a term used in the SADiE digital audio computer manual. A “Clipstore” is a list of exact sections of an audio programme stored in SADiE, and the stored clips themselves. The “sections” are created by the sound editor as he edits on SADiE. These sections of the soundtrack are stored as a computer file in the SADiE and are called “Clips”. The list of clips appears in the Clipstore for the soundtrack being worked on. When one is creating a soundtrack, using Clipstore is like keeping a bunch of small reels of tape recordings all prepared and sitting on the shelf ready to be “spliced” into the appropriate place in the audio programme.
CLOCK, CLOCKING (Word Clock): (See WORD CLOCK.)
CLOCK JITTER: A “clock” in this sense is an electronic circuit that generates an exact timing signal that is used by a machine to run itself. In digital recording and playback (audio or video) “clock jitter” refers to the machine running unstably (jittering) because it cannot get a stable clock reference. This can cause the audio and pictures to be distorted.
CLONE: A perfect copy of a VIDEO EDIT MASTER. It is a recording made of the final master video edit going directly between the source machine and copying machine and the recording is closely monitored and verified. The clone can then be used to produce further copies and the original master safely stored.
CLOSED CAPTIONED: A caption is a title, text, explanation or additional illustration that is part of a television broadcast, film or video. On many TV broadcasts or videos, there is an additional feature called a “closed caption”. The word “closed” as it is used here means not displayed without special access. (One has to “unclose” it in order to see it on your TV screen.) An example of a “closed caption” is translated subtitles that appear at the bottom of a TV set. For hearing impaired persons, a closed caption can be accessed to appear on the screen so anything said by the actors or newscasters is also printed right on the screen. If not selected on the TV’s menu, no captions will appear on the screen.
CLOSED LOOP SYSTEM: A mechanical design on an audio tape recorder used for professional grade audio recordings. It concerns the “transport” - that mechanism which moves the tape from one reel to the other, passing it in front of the machine’s record and playback heads. A closed loop system is used in some brands and models of tape recorders. The transport on this type of recorder has two capstans running at slightly different speeds so that the tape is fed to the heads slower than it is taken away from them. This causes the tape to stretch very slightly, providing a constant tape tension. A closed loop system has very constant tape speed so the recording sounds extremely stable as a result.
CLOSED-FIELD MONITORS: A British term for “near field monitors”. (See NEAR FIELD MONITORS. )
CLOSE-MIC’ED: It is a physical characteristic of microphones that when they are very close to a sound source certain qualities of the sound (especially the bass frequencies) are accentuated. “Close mic’ed” means that the microphone is placed within several inches of the sound source to take advantage of these qualities. As an example, some radio announcers do this so their voices sound very big and authoritative. Another purpose for close mic’ing is to isolate one instrument or voice from another. When a microphone is placed within a few inches of a sound source, sounds which are a few feet or more away from it are barely picked up by that mic in comparison. In a live performance this enables instruments and voices to individually be clearly heard by the audience. The technique is also used in studios when several musical instruments are played at the same time to keep their sounds separate from each other in the recording.
CLOUDY: 1) Descriptive of a mix that does not have good clarity and its various sounds are blurred and ill defined, as if there is a cloud covering the sounds. 2) A poor recording or recording copy that does not have good presence and clarity as if the recording machine was not operating well, resulting in sounds which are slightly less present, muffled, and not distinct. 3) If there is a bit of background noise or hiss on a recording or in a mix, it can “cloud” the mix preventing one from being able to hear all the finer details and nuances that one should be able to hear.
CLUTTERED: An audio mixing term used to describe a mix wherein there appears to be too many instruments and vocals making the presentation sound too “busy” and congested. The instruments in the mix are not distinct, but have too many random sounds sort of bumping into or sitting on top of each other. Or there are just so many sounds or sounds which are similar in a mix, that nothing really stands out and grabs a listener’s attention.
.CLS: .CLS stands for Clipstore. This is a specialised designation used in SADiE - covered in its manual.
CMX: This is a term found in the SADiE digital audio computer manual. An EDL format developed by a no longer extant Canadian company, used by AMS Neve and supported by SADiE, Avid and other systems. CMX was one of the original EDL formats. AMS Neve equipment no longer uses CMX, but SADiE can handle these types of EDLs if needed.
COAST (COAST RECORDING): A company located on Santa Monica Boulevard in Los Angeles that buys and sells audio equipment, both new and used and also supplies tape and accessories.
CO-AX, COAXIAL CABLE: This is a type of wire (cable) mainly used for video picture signal when hooking up a video recorder or TV monitor. Co-ax cable has two conductors. The first is one single solid wire positioned in the centre of the cable. It is surrounded by a non-conductive material. The second conductor is made of braided metal and is wound around the non-conducting material. A sheath of vinyl is applied to the outside of the cable to protect the conductors. The first conductor is exactly in the centre of the cable and therefore also precisely centred inside the metal braid of the second conductor. Both conductors share the same “centre.” “Co-ax” is short for co-axial. The prefix “co” means jointly or together. The word “axial” means located exactly around a centre line. Therefore the term “co-ax” describes the two conductors sharing the same centre or “centre line.” Its co-axial design and how the signals flow within the cable’s two conductors effectively prevent interference from entering the cable from outside electromagnetic fields. Such fields exist in electronic equipment, wiring, electrical outlets and circuits. They can cause distortions and lower-quality video pictures. Even local radio stations may have such a strong signal that they can interfere. Co-ax is not susceptible to picking up interference from external sources. There are over 50 different grades of co-ax. The kind used depends on the requirements of the installation. These grades are designated by letters and numbers which make up a grading system for all types of co-ax. For example, one type of co-ax cable is called RG58/U. The “R” stands for radio frequency, “G” means made for the US government, “58” is the government approval number for wire rated as suitable for general purpose use. The “U” stands for universal specification meaning that this numbering system is standardised, accepted and widely used throughout the industry.
COAXIAL: Sharing the same axis, meaning two or more items are mounted in the same line as each other. Such as in a loudspeaker cabinet that has more than one speaker element (i.e. a woofer and a tweeter). If both are mounted in the same line straight up and down (the tweeter is not off to either side from centre) then the cabinet is said to have a “coaxial” design. Many loudspeakers are designed this way - with all speaker elements in the cabinet in one straight row vertically. This arrangement gives a “point source” to the sound. Point source refers to a design in loudspeaker systems where even though separate speakers may exist in the loudspeaker’s cabinet, all the sound from them appears to emanate from just one point. They blend together so well, the sound just comes from one location, even though several individual speaker elements may be reproducing the sound.
COBALT: Cobalt is a type of metal similar to iron and nickel. It has good magnetic properties and is often used in the making of audio cassette tape.
CODE: The “language” of numbers, letters and-or symbols representing the data and instructions capable of being read, transferred, recorded, and otherwise processed by computers or computerised devices.
CODED: Many audio signals are “coded.” For example, the soundtracks that are on a DVD video disc are actually “coded.” They are not on the disc like they are on a cassette. Even though there may be 5, 6 or even 7 channels of audio to create the surround sound for the film, all those “tracks” (channels) are not actually on the DVD. Rather, all the audio has been “coded.” It is all just one code. It is just one digital “stream” of information. The code is read by the DVD player and the player is able to “decode” it back into the many channels of sound. 2) Often a code, or coded instruction, is included in digital audio or video information. For example, if you play a DVD-Audio disc, but not on a surround sound audio system, you can press a button on the DVD Audio player to play only a stereo version. There is a code with the DVD-Audio disc’s sound that tells the DVD player how to convert the sound to a stereo version. The instructions are “coded” into the information on the disc.
CODEC: Any compression or decompression process for reducing the size of a data file (compressing it to fit), then restoring it when required (decompression). Such a process allows full movies and their soundtracks to be fit onto a DVD.
CODING: When a CD for a lecture, book to tape or music release is being produced, the sound editor uses the SADiE computer to add codes to the computer file containing the lecture or music. This action is called “coding.” The codes are simply the track numbers that appear in a CD player’s display window that you can use to cue up to the part of the CD you want to hear.
COFDM: European Digital TV (DTV) standard. Acronym for Coded Orthogonal Frequency Division Multiplexing. (Technical write-up at glossary entry VSB.)
COINCIDENT MICROPHONES (COINCIDENT PAIR): Two microphones whose pick-up heads are placed as close as possible to each other so that the distance from any sound source to either microphone is, for all practical purposes, the same. Hence they “coincide” (are “coincident”).
COLLAPSED DOWN (to stereo), COLLAPSE DOWN: To convert a surround sound multi-channel mix (music or film) down to a mix that requires fewer loudspeakers, such as a stereo (two channel) version. Also called fold-down and downmixing.
COLLAPSED SOUNDSTAGE: 1) When a mix sounds small in size (lacks space and dimensionality), the term “collapsed soundstage” may be used. 2) Poor audio electronics and loudspeakers can “collapse the soundstage” of a good mix.
COLOURATION, COLOURED: 1) Any unwanted attribute of a sound that causes it to sound not natural or its sound to be not as pure and true as the original did before it hit the microphone. 2) Any undesired additive characteristic of a sound’s quality could be generally termed “a coloration”. Some microphones, audio electronics and loudspeakers can add their own “coloration” to a sound. Usually this is unwanted. However, under some circumstances it is intentionally done - like a famous brand of old guitar amplifier has is own “coloration” that sounds great for rock and roll.
COLOUR BARS: An electronically generated video signal which contains bars (vertical stripes) of several different colours displayed on a TV or video screen. It is the most common video test and calibration and is used to adjust the colour and brightness accuracy of a video picture when recording and playing back.
COLOUR BURST: Also called reference burst. This is electronic data contained in the colour signal of a video picture that keeps the colour signals aligned so they don’t interfere with each other.
COLOUR CORRECTION: When the Film Lab makes a print copy or a negative copy, usually colour correction adjustments are done. “Colour correction” is also called “Colour Timing.” It is simply adjusting how long (how long a time) different colours of light are allowed to affect the copy during its printing process. One can, in this way, vary the colour of the film, shot by shot, using timing adjustments, so as to improve the look of each shot and make it consistent with the film as a whole. The amount of time that each colour of light is applied is adjusted with computerisation. Therefore, as the film copy prints, the colour adjustments occur precisely. Colour timing, colour correction is also the action of adjudicating what colour correction is required and how exactly to achieve that with adjustments of the lights.
COLOUR FILM: In the very early days of cinematography and still photography, only black and white film was used. Soon, however, motion picture filmmakers attempted to bring colour to their projected images. At first, dyes were used - the film itself was painted or dyed to create colour in the picture presentation. For example, fire could be dyed red. This dyeing technique goes back to Thomas Edison, the inventor of motion pictures, as early as 1896. A similar dyeing technique was used for still photographs. The black and white prints of the photos would be dyed to give the print some colour. Various other methods of adding colour were experimented with, including projecting film through a series of different coloured filters to produce a type of colour image on a screen. All these methods were attempting to produce colour from a basic black and white movie film image, and were thus referred to as “additive” colour processes. Such processes had a fundamental problem however. Each made the film’s image dimmer on the screen. The various layers of dyes, paints, filters, etc. all greatly reduced the amount of light able to shine through the film and arrive at the screen - making the image quite dim. The additive methods for creating colour motion film images was abandoned by the early 1940’s. Modern colour film has 3 layers of colour sensitive emulsion - one for each of the primary colours (red, green and blue). Because a given layer of the film records only one part of the colour image and rejects the other colours, it is called a “subtractive” colour process. A brief description of how this is done follows: Colour depends mainly on light. Although most light appears white to the human eye, it is actually a mixture of the three primary colours - red, green and blue. All colour perceived by the human eye is produced by a blending of these three basic colours. In colour film, layer 1 is sensitive to and records only the blue-coloured parts of image, rejecting (“subtracting”) the green and red. Layer 2 records green, but not blue or red, and layer 3 records red and is blind to both blue and green. When colour film is exposed, light strikes the first layer and forms an image of the blue areas of the scene. Then the light passes through the second layer forming an image of the green areas. Finally, light goes through the third emulsion layer and records the red parts of the scene.
For more information on the processing and development of colour film, read on… When colour film negatives are later processed (developed) after having been exposed, the developing process works in two main ways: First, an image is formed from each layer of the emulsion. (Each layer’s image being only part of the overall scene - the blue, green or red parts as mentioned above.) Second, a chemical “developer” activates a substance called a “coupler” in each layer of the emulsion. Couplers unite (“couple”) with chemicals in the developer to produce coloured dyes. The colours of the dyes are the complements (opposite colours) of the light from the original scene. Yellow is a complement of blue so a yellow dye forms on layer 1 (the blue layer). On layer 2 (the green layer), a magenta (purplish-red) dye forms, because magenta is the complement of green. The dye in layer 3 (the red layer) is cyan (bluish-green) which is the complement of red. A colour negative is made as a result of this developing process, with the dark areas light, the blue areas yellow, the green areas magenta and the red areas cyan. Complementary colours are used as dyes because they reproduce the original colours of the scene when the film is processed into photographs. This same basic process applies to both still and motion picture film. (Compare BLACK AND WHITE FILM.)
COLOUR FRAME (VIDEO): 1) A process used to encode colour information within the NTSC’s (National Television Standards Committee’s) standard of four colour fields per television video frame. One TV video colour frame sequence consists of four fields. A colour frame field is not the same as a television frame field. Fields 1 and 3 are defined as Colour Frame A, and fields 2 and 4 are assigned as Colour Frame B. Colour Frames are data that the video system uses to accurately and stably reproduce the various colours. The video carrier wave is the stable datum and variations in the colour frames relative to the carrier wave produce the colours on the video screen. 2) Colour Frame is also a type of time code that is referenced to the video signal. In the NTSC television system, the colour frame identification bit (bit 11) in the time code indicates that colour frame identification has been applied to the time code. This colour frame identification also indicates that even frame numbers coincide with Colour Frame A and odd frame numbers coincide with Colour Frame B. Also known as non-drop frame time code. Because of the nature of the NTSC colour television system, one hour of non-drop frame time code does not agree with one hour of clock time. Non-drop frame time code is 3.6 seconds longer than one hour of video information. Non-drop frame has been superseded by drop frame time code by the television networks and most independent stations. (There is more data at TIME CODE and DROP FRAME TIME CODE.)
COLOUR FRAME TIME CODE: See definition 2 of COLOUR FRAME.
COLOURIMETRY: The measurement and precise adjustment of colour. Applicable to the Film Lab’s colour timing process as well as in the field of video projection, which requires accurate presentation and adjustment of colours.
COLOUR TEMPERATURE: This is an important term in cinematography, videography and still photography. It also has much to do with correctly showing films on a projection screen. In all these technical activities, correct “colour temperature” settings are required. Colour temperature is a precise unit of measurement. “Temperature” could be said to be how hot a certain substance has to be heated up in order to give off various desired colours of light. There is a standardised substance used as the reference to establish this unit of measurement. It has as a technical name; “black body.” A “black body” is an ideal surface or object that can completely absorb any light striking it, reflecting none of it. It would be the blackest of blacks, as black totally absorbs all light. Colour temperature is measured on a “Kelvin” scale, named after Sir William Kelvin, an English physicist and engineer. It is based upon the stable datum described above - the ideal “black body” and its ability to absorb light, and emit it only when heated to certain temperatures. Because the ideal black body absorbs light and doesn’t reflect (doesn’t add any light or colour of its own), it burns at a pure colour corresponding to how much heat is applied - that’s why it is used as a standard. Daylight is approximately 5600 Kelvin, a common light bulb is about 3200 Kelvin. Colour temperature is of concern, for example, when adjusting the lamp used to create the bright light to project a film image onto a screen. The industry standard colour temperature for such a projector lamp is 5400 Kelvin, plus or minus 400. Our Rushes Theatre projector used for the quality control of films is set to 5400 Kelvin, plus or minus 100. This gives a very precise standard by which to judge the colour accuracy of a film. There are standard meters used for colour temperature measurement.
COLOUR TIMING: See COLOUR CORRECTION.
com: A computer term that is short for “communications port”. A port is a connection point on the back of a computer which allows data to transfer in or out to another computer.
1) Slang for a business organisation or business individual who conducts his business entirely over the Internet by running a full feature Internet site. “She works for a dot com.”
2) When someone wishes to access an Internet site, he usually types “.com” at the end of the desired site’s address name. By typing “.com”, the signal from your computer knows to access the port on the desired Internet site’s computer with which to access and receive the site’s content information.
COMBING and COMB FILTER: 1) To put a sound through any device that leaves closely adjacent frequencies up in level then suddenly down in level. For example, if one were to take a graphic equaliser’s many sliding faders and pull every other one down, and every other one up, then send an audio signal through the unit, one would have created a comb filter. It is called a “comb” filter as the closely spaced up and down faders look like the teeth of a comb - a tooth, then a space, a tooth, then a space, etc. This has limited application. For example, one can take a mono audio source, split it into to two signal feeds and run each through separate equalisers set up as comb filters but each with opposite settings (the faders that were up on one are down on the other and vice versa). If done well, because each channel is being made different, a sort of simulated stereo effect can be achieved. 2) Comb filtering, or “combing”, is also a term to describe an unwanted effect in audio where two similar audio sources are slightly out of time so that when they try to blend together they create a wavering or wandering sort of sound. The sounds are said to be “combing” (sweeping across) each other.
COMBINING AMPLIFIER: Short for “active combining amplifier”, an amplifier circuit that combines two or more signals into one. This type of circuit is used in mixboards and other audio equipment where two or more separate sound signals need to be combined into one.
COMBINING NETWORK: A “network” (routing) that allows two outputs to be mixed together without one output interfering with the operation of the other output. Electronic parts installed in the network prevent one signal from interfering with the other. Without the electronics, the two signals might combine, but they would “fight” each other at the same time so cause a drop in volume and increased distortion.
COMMANDING: Sound that is very powerful - to such a degree that it literally “commands” the listener’s attention and entirely moves the listener emotionally. Completely energising and huge in scope. Can’t be missed. Anyone listening absolutely gets it without any Q+A.
COMPACT DISC: (See CD - THE COMPACT DISC, WHAT IT IS.)
COMPACT FLASH IC MEMORY CARDS, COMPACT FLASH TYPE II: Abbreviated “CF”. A small integrated circuit (IC) memory card used to store data in some consumer digital equipment. Somewhat similar to Sony’s “Memory Stick”.
COMPACT HYPERTEXT MARK-UP LANGUAGE: See CHTML.
COMPANDER: The word is made up from a mixture of “Compressor” and “Expander”. (COMPRESSOR and EXPANDER are defined as separate entries in this glossary.) A “compander” is not a piece of audio mixing equipment. Rather, it is a circuit in some analogue audio recording systems that deals with handling low volume background noise that needs to be removed for a good clean recording. The Dolby and DBX companies have made noise reduction circuitry using compander circuits. As the recording is made, the audio is compressed and as the recording is played the audio is expanded.
COMPILATION TRACK: In recording songs, especially the lead vocal parts, often many tracks of recordings are made. The singer will sing the part several times and each is fully recorded. From these, the best sections of each performance are picked and transferred to one “compilation track”. The final compilation track is a collection of all the best parts the singer or musician performed. You don’t erase anything the singer does when recording a song. All his or her takes are fully recorded while moving through the song from the start to its finish. Often what was sung the first time or second time was great and is the best upon review. If he kept trying, and you kept erasing and recording over every attempt, you may have lost the best performance.
COMPLETE MIX (CM): See CM, definition 2.
COMPLEX WAVEFORM: A single test tone looked at on test equipment will give a very simple, pure looking wave - just one line that forms a wave up and down. A complex waveform has more than one tone (sound) and has many lines creating many waves all at the same time.
COMPONENT(S): Any individual piece of audiovisual equipment is commonly referred to as a “component”, especially in the consumer market. Many home consumers’ A.V. systems are made up of many different components. There can be the surround sound receiver or processor, a DVD-Video Player, a CD player, a tape cassette deck. Each of these is an individual component.
Component Video: This is a higher quality method of transmitting, recording and editing a video picture. It keeps the various colours of the video running separately rather than combining them, as is the case with “composite” video which “composites” (combines into one) such all together and sends the signal on one wire. The better method, called “component video”, keeps the signals separate. It deals with each “component” of the video signal as a separate aspect and uses different wires for the colour information, separate from the brightness information. This maintains a high quality colour and brightness of the picture. A component video signal is one in which the luminance (brightness) and chrominance (colours) remain as separate parts of the overall signal. The parts are kept separate when sending the video signal and when processing the video signal through editing and playback equipment. The signal is sent using wires that keep the components of the signal separate. This type of video signal best retains the maximum luminance and chrominance information of a picture.
COMPOSING: In music, the act of writing a song. It is coming up with the melody and concepts that are the genus of the song.
Composite Video: This is the type of video signal that much consumer video equipment has. A video picture is actually made up of different parts, such as the three primary colours. In composite video, all the parts are put together (“composited”) so they run all on one wire and are treated and handled together by the video equipment. This is not the best quality video. It is what you don’t want to use if you are playing a Super VHS video deck or DVD player. Composite Video is a video signal where luminance and chrominance are combined. The two are kept combined when sending the video signal and when processing it with editing equipment etc. It is not as high a quality as component video.
COMPRESSED TO FIT: 1) Some music Mixers use this term to refer to the process of taking a large number of musical instruments and singers and making them “fit” into the mix so one can hear each clearly and for each to have their own location and space in the mix. With surround sound music mixes, less “compressing to fit” is required as one is no longer only dealing with just two stereo speaker channels in which all the sounds must be “compressed to fit”. Rather, in surround mixing, there are 4, 5, 6, 7, or even more channels of loudspeakers all around the room and therefore less need to work to make them all “fit” together as in the presentation made by just two stereo speakers. 2) Said in regards to digital audio and video where compression is applied to enable all the picture and sound information to “fit” into a given amount of storage (computer storage) or to be transferred over digital lines to another location.
COMPRESSION1, COMPRESSED: In audio mixing, said when dynamics are restricted. Sometimes this is done intentionally by the Mixer, using mixing devices called limiters and compressors. Sometimes the sounds are compressed in error or it happens in error. Sound is said to be compressed when it does not have the natural loudness and softness one would hear if the instrument or singer were right in the room playing or singing live. “Dynamics” in the field of audio is the word that refers to the loudness range of a sound (from loud to soft.) When the dynamics are restricted (compressed), the sound is not allowed to go as loud as it could. Sometimes, a Mixer will intentionally compress the sound. In doing so, he brings down (lowers) the loud portions so these portions of the sound are under control. Often, in recording sounds, the dynamics can be exaggerated and even hurt one’s ears because the sound (for example, a trumpet or a loud electric guitar) is being picked up by the microphone in such a sensitive or strong way. By skilful compression in mixing, an instrument or voice can be made to sound fuller and richer, because often the bass part of a sound is lower in volume than the higher frequency portions of the sound. Higher frequencies (the sharp treble) can tend to blast and their dynamics can go out of control while the bass frequencies are less prone to such. With compression, the lower frequencies can be brought out, relative to the highs, and the sound made richer and given more warmth. The term “over compressed” means this treatment has been overdone.
COMPRESSION2, COMPRESSED: Similar to COMPRESSION 1 but said specifically in regards to audio loudspeaker systems when the speakers themselves and-or the electronics driving them are somehow limiting the dynamics of the sound being reproduced at normal volume settings on the equipment. The various loud portions of the audio programme are not allowed to play as loudly as they should be able to go. Note: This is different than how “loud” overall the speaker will play if turned all the way up. Equipment, when played at its maximum power rating will “compress” (run out of steam and therefore restrict and limit the loudest parts. Some equipment limits the loudness of the loud parts when played at normal listening levels. Any time equipment does this, it is called “compressing the dynamics of the music”.
COMPRESSION3: Used in reference to digital audio and video and the transmitting, copying, manipulating, storing and processing of such. “Compression” means squeezing (“compressing”) digital information (digital audio and-or video) so more can be stored in less space, such as an entire film and its soundtrack on a small DVD disc. Though called “compression,” it is actually the process of reduction of data information and the determining of what portion of sound and-or pictures can be left out as not necessary or “won’t be noticed” by the listener or viewer. The concept of compression is not new. Since the 1940s television broadcasts have been done with a type of compression. Digital audio and video equipment uses compression to “squeeze” the large amount of digital data required for digital sound and picture information down into a smaller “package” so more information can be stored in less space or to more easily send it to another location. Many types of digital equipment and media can’t handle the massive storage size of digital audio and video information. When this is the case, one must first “compress” the data down to a size the equipment can accept and deal with. In the case of the DVD disc, for example, if the film and its soundtrack were not compressed, the DVD would only hold about 15 minutes of the movie. Another example, music, when placed on the Internet, is often a compressed form of the very same music heard on a CD. A CD player can play all the digital data on a CD. However, the Internet itself cannot. Music placed on the Internet must therefore be “compressed” down before it can be transferred around to Internet users. Same with any video footage on the Internet too. Many other digital formats require compression. Compression is done using a computer programme. All digital audio-visual equipment is actually a sort of computer. The term “digital” implies “computerised” - “digits” are the language computers use to record and store data. Therefore, digital music and digital video are actually computer data - they are in a language, or code, a computer can read.
It is important to understand how compression is done and how it works. A very simplified concept of the process follows: Imagine watching a video of a man speaking while he stands in front of a blue wall. The wall is constantly the same. It never changes. Only the man’s image changes - his mouth, waving his arms, etc. Compression is done by a computerised circuit. It is somewhat “smart.” It looks at that picture of the man and says, “I’ll record the man constantly, but not the wall because the wall never changes.” Instead of recording the wall over and over and over, it just takes one picture of the wall and uses that. It only records the man and uses the already stored picture of the wall for the wall. The wall is always blue, always the same distance from the camera so, the computer circuit rationalises, “I won’t bother to record the wall.” Because the wall is not continually being recorded, there is less information to record and store for the entire shot. Therefore, the whole scene of the man and the wall can all be stored in less space. Because the compression circuit is “deciding” to intentionally discard recording the wall, it is said to be “throwing away” the wall - it decides to “lose” the wall. Therefore it is termed a “lossy” form of compression - it intentionally loses information and, instead, uses earlier recordings to replace images which have not changed. That’s the basic concept behind video compression.
But what about sound? Compression of sound works a little differently. The compression circuit is programmed to detect what sounds the listener (consumer) might not miss hearing. The circuit “listens” to the audio programme and seeks out sounds which are masked (covered up) by other sounds and decides not to record the masked sounds. If a particular sound is very loud, like a loud bomb going off in a movie, then the compression will not record other little sounds which the bomb’s sound is masking. The compression will also seek out sounds which are very similar to each other and “decide” that because one sound is so similar to the next, only one of them needs to be recorded. There are many different types of sound compression yet they each work in these ways. They try to process (compress) the sound in a way it is thought the “human ear” perceives sound. That word “perceives” is key - for it is for this reason that such compression methods for sound are called “perceptual coding.” And to some degree it is true how it works. For example, if you are in a busy restaurant talking to some friends, the persons speaking loudly right next to you might not even distract your own conversation. A loud group several tables over might not even be “heard.” And loud talking nearby might mask (obscure) the sounds of the kitchen cooking or silverware being set out by the waitress on the table next to yours. This is called “Auditory Masking” - it’s how the engineers who came up with the principles of compression decided to “trick” the audience as to what is recorded and what is not recorded. Of course, these compression processes deal more with subtle sounds. They actually don’t refuse to record an entire blue wall or all the yelling in a restaurant - but those are the principles upon which they work. It is a process of selection. The compression is deciding what sounds or picture information to toss - what to lose. Every single DVD movie video you watch has its pictures compressed in this way. Every movie you hear too, even in a movie theatre, has its audio compressed in this fashion.
Of course there are some very poor versions of compression as well as they compress way too much. For music releases, like those you buy from a record store, even an untrained ear can easily hear the difference between compressed and uncompressed. Audio does not sound as good when parts of it have been intentionally not recorded and some of the sound lost (thrown out). Therefore another type of compression was developed, one that does not lose any of the audio at all. Unfortunately, it can’t be used for film soundtracks because it only compresses a little bit - not enough to get a whole film plus the film’s soundtrack onto one disc. But, for audio alone, it works great. It was developed by a small English audio company called “Meridian” and is distributed by Dolby Labs. The Meridian process has now been adopted by the entire music industry as the compression it will use on all music releases being put out on a type of DVD, called the DVD-AUDIO disc. Compression of audio and video information is a major part of modern digital audio and video. There is quite a lot of information to be known about it, but the above are the basics.
COMPRESSION, DECOMPRESSION: See CODEC.
COMPRESSION, TYPES OF (video and audio): (See COMPRESSION 3.) The following is a list of the more common types of audio and video compression methods:
NOTE: There are many forms of video and audio compression used throughout the music industry, film industry and Internet related activities. In the list below are the more common in present time that one is most likely to hear and come in contact with.
Each format type is fully defined as a separate entry in
this glossary as are any technical words used below.
MPEG 1 - Moving Pictures Expert Group 1
This is the most basic form of video compression used commonly on the Internet and for other applications that do not require a high quality level. Pictures look almost as good as normal consumer ½ inch video cassettes. Lower quality than MPEG2.
MPEG2 is a higher quality video compression. It is used for many normal TV type broadcasts, sending decent quality video pictures over the Internet, and some DVD-Videos. There are different versions of MPEG2 that are higher quality. These are MPEG2 MAIN LEVEL and MPEG 50 and may be found separately listed here, and as entries in this glossary. (See MPEG.)
This is a higher quality MPEG2. It processes video pictures progressively. (See PROGRESSIVE SCAN.) It is therefore highly usable for DVD-Video discs containing feature films. See MPEG 2 MAIN LEVEL for more information.
This is the highest quality MPEG2 presently available. It is suitable for compressing Digital TV (DTV), including High Definition TV rates, such as 720 lines of resolution on the screen and higher.
MP4 is one of the latest MPEG compression formats with video applications. See MP4 below under audio compression section for details.
There are various media software which do video compression for downloading off the Internet and for other purposes. They frequently do not say what their compression scheme (method) is, but more than likely it is based on a low grade MPEG1 or similar compression format. Examples are Microsoft’s Windows Media 8, Real Networks “RealSystem”, and Agility Enterprise Encoding’s “ANYSTREAM” as used by CNN’s Internet site.
A brand of video compression for putting video information on the Internet. Similar to MPEG.
You may not have realised that interlaced television and video pictures are actually a form of compression - and have been all the way back to the 1940s. As only one half the lines of resolution are ever presented on the television screen at any one time, only half the lines of resolution information have to be transmitted and displayed at any one time, and therefore compression is accomplished. (See PROGRESSIVE SCANNING for more information.)
AUDIO COMPRESSION FORMATS
SONY SDDS THEATRE SURROUND SYSTEM
(Sony Dynamic Digital Sound) (professional use only)
Sony’s own system for surround sound in major motion picture theatres. Though it has 9 individual audio loudspeaker tracks, Sony compresses the audio down so as to create one digital data stream that is printed on the edge of the film. Sony’s system does not use any Dolby or DTS processing. It is a lossy compression format.
DOLBY DIGITAL (AC-3) and DOLBY E (professional & consumer)
Dolby’s AC-3 compression for film soundtracks & Digital TV (Dolby E) compresses at a level of approximately 12 to 1 to bring 5, 6, or 7 tracks of surround sound down to one digital stream on a DVD or to accompany a Digital TV broadcast over airwaves or via cable. It is high quality and is a complete encode or decode process that also utilises perceptual coding. It is a lossy format. The AC-3 basic format applies to all Dolby Digital surround sound formats of any designation both professional and home consumer versions where it is found on all home surround audio devices.
DTS (professional) (dts - Digital Theatre Systems)
NOTE: Not a compressed digital format but included in this list to make this distinction. Recording of film soundtracks for general cinema applications is onto CD-ROM with no particular alteration. This is for pro use only at theatres.
The DTS home surround sound format is a compressed lossy format which is similar to Dolby Digital as covered above. Found on many DVD Players and most all home surround electronics devices now being sold.
A lossy compression format for TV and video sound. Used on some DVD’s as well. More common overseas. Many USA products do not have the capability to decode such though the feature is becoming more popular in the States as well.
MERIDIAN LOSSLESS PACKING
The highest quality audio compression available. Developed by the Meridian company in England. Licensed to Dolby internationally. Used for creating DVD-Audio discs, not DVD-Video discs (which use MPEG2 for pictures and Dolby, DTS or MPEG for audio. Meridian’s packing system is lossless. (See LOSSLESS COMPRESSION.) It does a 1 for 1 reconstruction of the bits using its encode or decode process.
A lossy compression format that Dolby developed specifically for copy protection for music on the Internet using a form of MP4 compression and Dolby’s own protection coding. Sometimes referred to as MPEG AAC. (See DOLBY AAC.)
ADPCM (Adaptive Differential Pulse Code Modulation)
An audio compression method that can compress music on CD’s so that 20 hours of MONO music can fit on only one CD. Has applications for junk “musak” in malls and shopping centres over crummy PA systems. Also used for Interactive Multimedia CD’s, which require a lot of compression to store audio, picture, text and graphic information. (See ADPCM.)
This is the type of audio compression used in Sony’s MiniDisc systems. It compresses music to approximately one fifth its original size. (See ATRAC.)
Not to be confused with MPEG1, which is for video-audio. MP1 is strictly an audio compression that is intended for use when directly recording and compressing in “real time.” For example, it was used for the now defunct “Digital Compact Cassette” (DCC). That was a “real time recording” application.
Not to be confused with MPEG2, which is for video-audio. MP2 is used for the audio with Digital TV broadcasts. It is used to put audio on some DVD’s (mainly overseas), but not to be confused with the audio put on DVD-Video by Dolby and DTS processes, or how DVD-Audio discs are made. In Asia, MP2 is used heavily on Video Game CD’s.
This is the main MPEG audio format of compression. It is used for things such as putting music on and taking it off the Internet (streaming). Home consumers are making their own CD’s of music off the Internet - all in MP3. CD players are now available that play MP3 homemade CD’s as well as normal CD’s, plus there are many little MP3 players that store music in memory. New MP3 car audio products are starting to now come out as well. It sounds like junk in terms of serious audio applications.
MP4 is one of the MPEG compression formats that can be used for Internet transfer and downloading of music and video information. MP4 is also the type of compression Dolby is using in their “Advanced Audio Coding,” which is a copy protection code being adopted by the industry applied to music on the Internet.
A brand name of lossy compression for audio on the Internet. Similar to MP3.
An abbreviation for Windows Media Audio. Microsoft’s proprietary digital music recording and playback format and recorder-player intended to replace, or at least significantly compete with, MP3. WMA devices store music in half the digital memory space as those used in MP3 devices. Examples of WMA players are the pocket-sized Intel “Pocket Concert Audio Player” and the Sonicube “Rio 800” which can each hold up to 4 hours of music (at sub-CD quality, but reportedly better sounding than MP3). When you “rip” (copy) a song from a CD into a WMA device, it automatically installs copyright-protecting “digital rights management” tools into the copied file. This limits or completely prevents additional copies from being made, depending on the copy protection instructions programmed into the original material.
COMPRESSIONIST: See VIDEO COMPRESSIONIST.
COMPRESSION DRIVER: A type of loudspeaker cone or diaphragm designed to send its sound into a narrow throat or horn from which it is amplified and its sound qualities further altered. A compression driver is much like the mouthpiece on a trumpet. It, by itself, makes little sound, but it is designed to send its sound into the body of the trumpet, which alters the sound and amplifies it. Compression drivers are usually used more for high-powered speaker systems such as those used at live concerts. Their power, plus the horn that amplifies the sound, can really push the sound out into the audience. Most PA speaker tweeters are compression drivers, especially those which are called “horns”.
COMPRESSION RATIO: The word “ratio” means the relative or comparative proportion of one quantity to another, like the relationship of width to height, amount of flour to sugar when mixing cake batter, number of boys to girls in a school, etc. Ratios are usually expressed using two numbers and a colon is placed between them. For example a ratio of 2 to 1 would be written “2:1”. 1) “Compression ratio” is the ratio of data in the original uncompressed digital signal to the compressed version. For example, all Dolby surround sound compresses the audio about 12:1. DTS compresses about 4:1. This ratio should not be used as the only method to assess the quality of a compressed signal. In general greater compression can be expected to result in worse quality, but different techniques give widely different results for the same compression ratio. Results will also vary depending on programme content. (If you need more data, see COMPRESSION3.) 2) When using a compressor for mixing sounds, the compressor (or limiter) has a compression ratio - how much it is compressing compared to the original sound. (See COMPRESSION 1 for more data.)
COMPRESSOR: A piece of audio mixing equipment that becomes active when loud peaks in the volume of sound reach a certain high (loud) point. When the peak exceeds a certain amount, the equipment acts to reduce its volume. The speed at which this is done, and how much the sound is reduced (lowered) is adjusted by the Mixer. A compressor is used to even out loud volume changes. It differs from a limiter in that the output volume is gradually reduced by a compressor while in a limiter, the output volume is held (“limited”) to not being any higher than a certain sound volume level. Both limiters and compressors are used to control rapid shifts (peaks) in the volume of a sound. However, one can over-compress the sound if not careful making it sound lifeless and dead.
COMPUTERISED DVD PLAYBACK: For the best quality DVD picture presentation, the use of a computer to play the DVD can be done. (For more information and technical data, see HOME THEATRE PERSONAL COMPUTER - HTPC.)
COMTEK: The name of a company that makes radio transmitters and receivers.
CONCENTRIC DRIVER (LOUDSPEAKER): A loudspeaker where the tweeter is mounted inside the woofer. The woofer acts to help project the sound of the tweeter into the room.
CONCERT REMIX: A “concert remix” is a marketing term found on CD and DVD packaging containing a remix of a live musical performance usually in surround sound. Older live performances are often remixed into surround sound and released on surround sound cd’s or DVD’s.
CONDENSER: An older term meaning the same thing as the term Capacitor. (See CAPACITOR.)
CONDUCTIVE PLASTIC: Plastic generally does not conduct electricity. However, by impregnating it with metal particles it becomes “conductive plastic.” Some of the volume controls (also referred to as “faders”) that you find on mixboards, preamplifiers, radios and other audio equipment are made with conductive plastic. They change the volume of sound by changing the amount of electricity flowing through them as one adjusts them. Therefore, they are “conductive.” Another use of conductive plastic is as a protective layer inside some audio wiring and cables. Audio signals flowing in wires are susceptible to interference from things such as nearby AC electricity power, radio transmissions, etc. Conductive plastic is sometimes used as a form of shielding to protect against such interferences.
CONDUCTOR: 1) A material, such as copper or silver, which allows the flow of electricity. 2) The leader of an orchestra who directs during a performance, and actually works out and interprets the piece of music to be played in terms of how the various musicians are to perform it and how the whole piece comes together.
CONFIDENCE MONITORING: See glossary entry “E to E” for full definition of confidence monitoring.
CONE: On a loudspeaker, the large area of hard paper or other material that moves to produce sound. It is shaped somewhat like a cone, so called “the cone” of the speaker. It is what moves the air so you can hear the sound. It’s what you see when you look at any common loudspeaker with its cloth or grill removed.
1) To set up a mixboard for a certain type of mixing. When doing a surround sound mix, the mixboard is configured a different way than when doing a stereo-only mix.
2) To establish the parameters and operation of any type of audiovisual equipment. Often this equipment is now computer controlled and the settings can be configured to perform operations in certain ways at certain points in time.
3) A DVD-Audio player will configure the musical content on a DVD-Audio disc into different versions which can then be played on a consumer’s audio system. For example, if the consumer only has a two speaker stereo system, the player can be told (by pressing a button) to configure a stereo version of the music, which is normally intended to be played in surround sound.
CONNECTORS, types of: A connector is a coupling device for joining two cables, or connecting a cable to a piece of equipment. Connectors are male or female according to whether they plug into or receive the mating connector. (Following is a list of connectors commonly used in audiovisual production and equipment.)
Technical terms are used to describe the following
connectors and many may be found elsewhere
in this glossary or in standard
Barrel - An adapter used to extend cables by plugging one cable into one end of the barrel and another cable into the other end.
Camac - A small 2 conductor audio connector that has a gold pin that is covered by a plastic sleeve in its centre, and a metallic casing on its outside. An example of the use of camac connectors is on the back of Gold’s Master Stereo Preamps (MSP).
Camlock (power connector) - Large single conductor twist-lock electrical power connections that are heavily insulated.
Crimp lugs - A two prong fork-ended connector that does not require solder. These are pressure-fitted onto the end of a wire with a crimping tool.
DB 9 - “Data Bus 9 pin” - A connector often used for computer hook-ups.
DB 25 - “Data Bus 25” - A 25 pin connector (similar to the DB-9) that is used for interfacing some digital audio recorders.
Dip socket - A receptacle that is soldered onto a printed circuit board so that a chip (integrated circuit) can be plugged into it and unplugged without having to solder the chip and de-solder it, which can ruin both the chip and the circuit board.
Edison - A standard 3 prong US electrical power connector.
Elco - A multipin connector used in connecting equipment in racks to patch bays.
F Connector - A small screw-on 2 conductor connector often used to hook up televisions to VCRs and to connect television antennas to a TV, VCR, etc.
Fisher - Any of various connectors made by Fisher. Examples are the connectors that are on the MSP-1 power supplies and on the Arriflex 535 camera that connect the CPU and the time code output. Fisher also makes camac connectors.
IEC electrical wire and connector - The type of power cable on electronics equipment that is removable. Has a flattened three conductor female connector that goes into the equipment and a normal wall power connector on the other end.
Hardwire - This means to connect the wire directly to the equipment without the use of a connector. The wire is usually soldered directly onto a point on the input or output of a printed circuit board internal to the equipment.
Jumper - A small wire that connects or “jumps” a gap on a printed circuit board, a wire or a connector. If you look at a printed circuit board you will see many paths that can carry signals. These are called “traces”. A jumper can be used to connect 2 traces together.
Lemo - A connector basically the same as the camac, but made by the Lemo Corp.
MTA - (Mass Terminal Assembly) - A connector that is often used on printed circuit boards to connect the board to incoming or outgoing wires - for example it is the plug-in connector mounted on E-Meter circuit boards.
Neutrix - A company that makes high-quality audio connectors.
Phono Connector - A 2 conductor connector that is used very often in home stereos. It was originally used to hook up a phonograph turntable to its preamp. It is now also used to hook up cassette decks, VCRs and other A.V. gear. Also called an RCA connector.
Phone Plug - A ¼ inch 2 or 3 conductor connector commonly used to connect instruments to amplifiers.
PJ 51 - These are the connectors that are used in many patchbays. They are a 3 conductor connector with a tip, a ring and a sleeve.
RCA - See phono connector.
SpeakOn - A high quality loudspeaker connector that can be used for 2 or 4 conductor cables. It has inner conductors surrounded by a plastic sleeve and has a twist-lock. These are used a lot in PA system speakers. For example, they are used to connect Gold’s international event podium monitor speakers to their amplifier.
S video - A connector used for hooking up Super VHS video decks.
TDIF - Abbreviation for Tascam Digital Interface Format. (See TASCAM.) This is Tascam’s interface that uses a 25 pin connector to send and receive 8 channels of digital audio and a “word clock” timing signal (see WORD CLOCK). It is used mainly with Tascam’s 8 channel digital audio recorders, such as the DA-88 and DA-98 models.
Terminal strip - This is just a row of screws that are isolated one from another by plastic. They are mounted together as a unit and many individual wires can be connected to the strip.
Tiny Telephone (TT) - This is the miniature version of the PJ 51 connector and is also used in some types of patch bays.
Tip Ring Sleeve (TRS) - The electronics name for a phone connector (plug), large or small in size. It has a small tip, a ring that is separated from the tip by insulation and a collar (sleeve) that is separate from both. The tip of the connector is hot (+), the ring is low (-) and the sleeve is ground.
Turnaround - An adapter that will allow 2 connectors of the same gender to be hooked up together.
Whirlwind - (Mass Connector) these are huge multipin connectors that are usually used to connect cable snakes for live events and performances. They are put on the ends of snakes that can have as many as 48 separate pairs of conductors in them and are used to hook up the house mixboard to the main stage, or the truck to the house, etc.
XLR - This is a 3 conductor connector that is very commonly used for microphones and for many different types of audio gear. Microphone cables almost always have XLR connectors at each end. “XLR” has no particular significance as an abbreviation for anything other than this type of a connector.
1) Another name for “mixboard” - the large central control station in a music or other mixing studio used to blend all the sounds together for a song or a soundtrack.
2) Any panel or series of panels containing the controls and indicators (lights and meters) for any electronic system.
3) In some home audio systems the “console” refers to the operational control centre that houses the volume controls, tone controls (bass and treble), switches, etc. This is a somewhat older term for home use. Sometimes these older consoles included a TV set too - the TV console or stereo console.
4) Any control station where there is a lot of audiovisual equipment, such as in a video editing bay.
CONSOLE REAL ESTATE: Slang - The capacity of a console to handle audio and-or video signals. For example, the number of individual channels in a mix board. A small mix board hasn’t much “real estate” to deal with a large number of separate audio signals.
CONSONANT: Agreeable to the ear; pleasant-sounding. The word “consonant” comes originally from Latin meaning, “to sound at the same time, agree, harmonise”.
CONSTRICTED: 1) Poor reproduction of volume dynamics. Dynamics are compressed. 2) Distortion at high volumes. 3) The sounds in the mix are small with no size, no space.
CONSUMER ELECTRONICS ASSOCIATION: See CEA.
CONSUMER ON DEMAND: Home consumers (home TV viewers) may now purchase an electronic device called a PVR - Abbreviation for Personal Video Recorder. (Such as the brand names “TIVO”, “REPLAY” and “SHOWSTOPPER”.) These are electronic boxes that sit on top of a home TV which allow one to record TV programmes digitally in memory and play the programmes back in any sequence desired at a later time. Therefore, TV programming is provided on the consumer’s demand (what he wishes to watch and when he wishes to watch it.)
CONTACT MICROPHONE: A microphone that picks up vibrations by being directly attached to the surface of that which is being recorded, and puts out an audio signal that replicates the direct vibrations. Contact microphones are sometimes used to record such things as drums, pianos and acoustic guitars.
CONTACT PRINT, CONTACT PRINTER: The Film Lab has two contact printers. They both do the same functions. They can produce a copy of a film by running a film’s negative together with (in direct “contact” with) the film to be printed on. Both elements (film and negative) physically contact each other and pass in front of light directed at them. The light transfers the image from the negative onto the film. Because each are in direct contact, there is a perfect transfer, frame by frame, of the picture’s content and size. The “Schmitzer” (brand) printers in the Film Lab are wet gate contact printers. (SCHMITZER and WET GATE are defined in separate entries.) The Schmitzer printers are specifically used to produce RUSHES PRINTS, INTERPOSITIVES from the ORIGINAL CAMERA NEGATIVES and the few 35mm RELEASE PRINTS that are sent to orgs such as Flag and Freewinds which have 35mm projection systems. They are not used to run off the 16mm release prints that are sent to orgs. They are too slow to be used for that purpose.
CONTENT OWNER: A music studio or music distributor or musician or composer who owns the music “content” one hears on a CD, DVD, off the Internet, etc.
CONTENT PROTECTION FOR PRE-RECORDED MEDIA (CPPM): This is a digital copy protection code for DVD’s, including DVD-Audio discs, to protect them from being copied illegally. CPPM works as follows: When a DVD is made, its video content is scrambled. When one inserts a DVD into a DVD player, the player looks in a special area of the disc for an encrypted “key,” a special digital code that must be decrypted (decoded) in order for the DVD player to be able to play the DVD’s content. When the player finds the key on the DVD, the player then uses a special computer programme that can decrypt the key code. The player then uses key code to unscramble the rest of the video data on the DVD so you can see and hear it. CPPM is added by the DVD duplication plant when you send a DVD master to be replicated. As this can markedly affect picture and audio quality, the duplication plant’s adding of CPPM should be known about and checked to ensure their equipment imposes no degrade upon the quality of the DVD itself. (There are many different types of copy protection codes used throughout the audiovisual industry. More data can be found at COPY PROTECTION, COPY PROTECTION TYPES OF, HOME RECORDING ACT, SECURE DIGITAL MUSIC INITIATIVE, CPRM, 4C GROUP, WATERMARKING.)
CONTENT PROTECTION FOR RECORDABLE MEDIA (CPRM): This is a digital copy protection code for recordable DVD’s to protect them from being copied illegally. See CPPM for general description on how this type of copy protection works.
CONTENT SCRAMBLING SYSTEM: See CSS.
CONTEXT OF THE MIX (in the): A given sound or sounds are “in the context of the mix” when they are correctly integrated into the overall presentation of instruments and vocals.
CONTEXT WITHIN THE ROOM: This is a mixing term regarding mixing equipment that can create the ambiance (the reverberation qualities) of different sizes and types of halls, auditoriums, rooms, concert halls, etc. The Mixer literally creates a “room” by using such a device or an actual echo chamber. The Mixer places the sounds he is mixing so each assumes the “context of the room” (takes on the character and quality of being in that room or “environment” the Mixer is working to create). Therefore the individual sounds are made an integral part of the mix.
CONTINUITY: 1) A continuous (unbroken) path for electrons to travel. 2) How an audiovisual product flows in terms of message, sensibility and rapport in all respects (shooting, editing, music, etc.). This is fully explained in the book, “The 5 C’s of Cinematography”. 3) The consistency of volume and other qualities throughout a music or other audio production.
CONTOUR: A graph of how some quantity changes with frequency. A frequency response graph is one type of contour.
1) The difference between dark and light areas in a film or TV screen. A screen or film presentation with good contrast will present all the various shades of grey from the lightest to the darkest. Poor contrast will jump (skip) some of the shades and go quickly from light to dark.
2) In audio, the term has a similar meaning. The various differences in sound are clearly audible. It is used when describing or pointing out differences in sounds and their qualities in a mix. For example, if many singers are recorded together at the same time, even though their various voices and the qualities of each combine into one presentation, their individual differences can still be heard, if they are recorded well so as to hear their “contrast.” This is called “good contrast.” Bad contrast is when one is unable to discern different sound qualities that should be there to be heard. One can’t hear them or the relationship of one sound to another or others clearly.
3) If a sound does not go well with other sounds or if a pictured object does not go well with other pictured objects, they are said to have “bad contrast.” Good contrast, in this usage, would be when everything goes together well and makes sense.
CONTROLLER: 1) Any device that controls another. There are video controllers and audio controllers. This is a term used in professional AV studios for the devices that one uses to specifically control the operation of other equipment, such as tape recorders or video machines at a distance from where one is sitting. 2) A “Digital Controller” - the name for audio preamplifiers that have full Dolby, DTS and other forms of surround sound electronics, but no amplification for powering loudspeakers. They usually have no AM-FM tuner (so can’t be called a “receiver”) - but some companies include such anyway and still use the word “Digital Controller” or “Controller”. 3) In MIDI (Musical Instrument Digital Interface), a device that generates a MIDI signal so as to hook together two or more digital musical instruments with one instrument able to control the others.
CONTROL ROOM: 1) Also called a “mix room”. The room or rooms in an audio production facility where all the mixing equipment and mixboard are located, as opposed to the “studio” (the recording studio) which is the room where the performers are recorded. 2) Any audiovisual facility which has audiovisual equipment being used for recording, signal transfer or broadcast such as at a TV or satellite station.
CONTROL TRACK: A signal recorded onto video tape as a reference for the running speed of a video tape recorder, for the positioning or reading of the video tracks and to operate a tape counter. A “control track” is the equivalent of sprocket holes on film, which are exactly spaced so the film can be shown at an exact speed.
CONTROL VOLTAGE: A voltage used to regulate an electronic device. Example: When a control voltage is sent to the control input of a device so equipped, its audio volume is determined by the amount of the control voltage. The higher the control voltage, the louder the volume and vice-versa.
CONVERTER (digital) RATES: See D to A CONVERTER and DIGITAL RATES for definition and full listing of rates.
CONVERGENCE: “Converge” means to tend or meet at a point or line - incline towards each other - as lines that are not parallel. It is also to combine or to come together for a result. 1) An example of “convergence” is the alignment of the green, red and blue light guns on a video projector. This must be done whenever a video projector is set up, such as at an event. It gets all the colours sharp. An unconverged video projector may have green or red glowing outlines around objects on the screen. 2) There is a marketing meaning of the term “convergence” in the audiovisual industry, meaning a combining of all types of audiovisual formats and computers for consumers. Home audio equipment manufacturers, Internet service providers, the film industry, the music industry and the video game industry are “converging” their formats so the home consumer will go to his home entertainment centre, and call up movies, music, Internet, video games, order goods through on-line catalogues, etc. They also provide phone services via the same system. They also can run surveys on the consumers to be able to tell what they like to watch and listen to and to then use this for marketing purposes.
1) The process of changing an audio or video programme from the analogue format to the digital format or to change a digital audio programme to an analogue signal. The latter is the case when CD is played. Its digital signal is converted to analogue so it can be played over loudspeakers or headphones.
2) Around the world, different types of TV’s and videos exist. Videos made in the United States will not play in all European countries as their video specifications and electronics are different. A conversion is required from one format to the other so it will play back on the video players in a given region.
CONVERTER: See CONVERSION, ANALOGUE, DIGITAL, D to A CONVERTER, and A to D CONVERTER.
COOL: A quality of sound where one perceives a lack of richness in the overall timbre of instruments, vocals or overall mix. Missing just a bit of lower midrange and upper bass frequencies.
CPU: Central Processing Unit - the microprocessor (“chip”) in a computer that does all the logic and processing functions. The CPU processes the instructions contained in the computer’s software, running through millions of instructions per second. The CPU stores and retrieves data to and from the computer’s memory
COPY CODE: See COPY PROTECTION.
COPY GUARD: A name sometimes used for the copy protection code put on DVD Audio discs. (See COPY PROTECTION.)
COPYIST: A skilled audio engineer who specialises in making perfect copies of recorded audio programmes.
COPY MACHINE: Any audio or video recording device that is used to make a perfect copy of an audio or video programme. There are many different types of copy machines. For example, an audio computer such as SADiE can be used as a “copy machine”, especially when LRH lectures are loaded into it for CD or DVD production.
COPY MASTER or ARCHIVES COPY MASTER: A perfect copy, of an LRH original recording. It is the Copy Master (abbreviated CM) that is used by the Lecture Mix Team to mix the LRH lectures we release. An entire Copy Master library of all LRH lectures is located in the A.V. Storage Building.
COPY PROTECTION: Copy protection is the method of adding a digital code to music or images, such as a movie put on a DVD. This additional code then blocks and prevents copying of the material. For example, some music over the Internet is protected by a coding process developed by Dolby Labs called “Advanced Audio Coding” (AAC). It allows a person to download a song from the Internet, but no further copies of that downloaded song can be made. AAC coding scrambles the song if anyone tries to make a copy. Certain types of coding can degrade the audio or picture, so testing is required before copy protection codes are added.
COPY PROTECTION (types of): There are many different types of copy protection used for both video and music releases. The most common are as follows:
COPY PROTECTION TYPES
All words and technical terms below are defined
elsewhere as entries in this glossary where much
more detailed information is given regarding the
various types of copy codes listed.
For Compact Discs (CD’s) (Also used in DAT machines)
Serial Copy Management System – SCMS
Used for all CD’s but is not buried into the music but kept totally separate from the music content so quality is unaffected. Allows a digital recorder, such as a DAT recorder, to record the CD but then that copy can only be copied by another machine once.
A type of copy protection for CD-ROM’s. SafeDisc installs a digital code onto the compact disc. The code cannot be copied or transferred from the originally purchased CD-ROM. The SafeDisc code is designed to cause any coping of the CD-ROM to abort.
DVD Player (lack of digital outputs for picture content)
DVD players do not have digital outputs for picture content. This prevents direct digital copying of the DVD disc. Instead, DVD players only have analogue video outputs. This is why you will get a far better picture if you play a DVD video disc on a computer with a digital output and send that digital feed to a digital video projector.
Content Protection for Pre-recorded Media - CPPM
Used to copy protect all types of DVD’s that one purchases, including DVD-Audio discs. It is not “Watermarking.” (See Watermarking below.) CPPM used to be called “CSS”. (See CSS below.) Also sometimes called “copy-guard”.
CONTENT SCRAMBLING SYSTEM 2 - CSS 2
This is actually the very same thing as CPPM listed above. CSS’s name was changed to CPPM because a 16 yr old Norwegian boy cracked the confidential computer code used in the first version (CSS 1) A new code (CSS 2) was developed and the name changed to CPPM.
Used in the production of DVD-Audio discs only. May have some applications for Internet music. The Watermarking code not only identifies the music and artist by displaying such on DVD-Audio players, but it also helps prevent copying as the code will not copy to an unauthorised copy made. This is not a mandatory code for all music products and is now under scrutiny as it is apparently audible in the music itself.
For Recordable DVD’s
Content Protection for Recordable Media - CPRM
Same type of coding as the CPPM listed above but for use in copy protecting digital discs which one can record onto, such as recordable DVD’s.
For Digital T.V.
Scrambling for Cable TV carrying High Definition TV signal to consumers. See DYNAMIC FEEDBACK ARRANGEMENT SCRAMBLING TECHNIQUE.
The intentional lessening of lines of resolution when feature films are broadcast for any sort of TV playback (satellite, cable, DTV or Internet). To “Dumb Down” is a form of copy protection desired by major film studios to prevent direct digital copying of films at high definition rates. Though the film may be produced for video playback at 1080 lines of resolution on the screen, the picture is intentionally reduced to only 600 lines. (One definition of the word “dumb” is “lacking some usual property, characteristic, etc”.)
DirecTV High Definition feed cut off
The DirecTV company has required makers of set-top boxes (Digital TV receivers) to include a circuit which shuts off High Definition TV reception at a programme provider’s request. DirecTV did not immediately activate the feature on any set-top receiver box, but the inclusion of the shut-off circuit was essential to get Hollywood to allow its movie and other content to be beamed to homes, per DirecTV. The stated concern was that the movie could be copied, then placed on the Internet for public access without payment. The circuit can also detect if a digital recorder is connected to the set-top box and, if so, shut down the High Definition feed.
POINT OF DEPLOYMENT (POD), HOST INTERFACE
Equipment and methods used to prevent unauthorised reception and-or copying of digital cable television broadcasts by consumers who have not subscribed to and paid for their digital cable TV service. Consists of computerised signal scrambling equipment on the premises of the Cable TV company (the “point of deployment”) and a box in the consumer’s home (the “host” box) which receives the signal, unscrambles it, and routes it to the consumer’s set top box. The host box is actually a separate addition to the Cable TV receiver box, which the home consumer must also have in order to receive Cable TV stations. (For a more detailed description, see POINT OF DEPLOYMENT, HOST INTERFACE at its separate entry in this glossary.)
FOR INTERNET MUSIC AND VIDEO
ADVANCED AUDIO CODING - (AAC)
This is a copy protection system made by Dolby for putting music on the Internet. It has now been widely adopted and approved by the music industry. It uses a recent type of MPEG compression (MP4) plus Dolby’s coding methodology.
SECURE DIGITAL MEMORY CARD
This is a small postage-stamp-sized memory card used in certain digital music players. It was developed by the electronics companies Matsushita (who owns Panasonic and other companies), SanDisk and Toshiba. Songs downloaded from the Internet would be playable on a personal computer using authorised software or the small player itself, but the music company could prevent songs from being burned onto a CD or posted to Internet music sites in playable form.
DIGITAL RIGHTS MANAGEMENT
This is a type of copy protection developed and used exclusively by Microsoft for its Windows Media Audio (WMA) Internet music format. Digital Rights Management copy protection is not embedded into the audio content at all. It exists only in the large server computer that supplies music for websites supporting and providing WMA. When a consumer logs onto the website, the Digital Rights Management system simply verifies that he is a paying customer. If so, access to the file is granted and if not it is denied. Digital Rights Management doesn’t prevent any further copying of the material once the consumer has paid for his original copy.
FOR DIGITAL VHS
High-Bandwidth Content Protection. This is a powerful copy protection for video incorporated into Digital VHS tape releases. It is considered an even more secure form of copy protection code than that used in DVD’s (which is called CSS, “Content Scrambling System”). HBCP is used to copy protect High Definition video releases of major movies. (DVD is not a High Definition format.)
CORNER MONITORS: In audio, monitors are loudspeakers and this term means the same as CORNER SPEAKERS. (See below.)
CORNER SPEAKERS: In a surround audio system, the corner speakers are the left front, right front, left rear and right rear. For optimum sound, they are not actually stuffed right into the corners of the room but usually out a bit so they have some open space in which to make their sound.
COUNTER NUMBER: All audiovisual recording and playback equipment (tape recorders, VCRs, etc.) used in a studio have a numerical readout that, depending on its setting, tells one the amount of time remaining in the programme (on the tape) or number of inches or number of feet that have passed or which remain to be played or recorded upon.
COUNTRYMAN: Brand name for a microphone named after its inventor, Carl Countryman.
COUPLING: 1) When a loudspeaker is set directly on a surface (such as a floor), the sound produced by the loudspeaker transfers into that surface. The surface and the loudspeaker (its cabinet, etc.) are now interacting together. They are coupled - this is called “coupling”. If the surface vibrates much, it adds its own sound to that being reproduced by the loudspeaker. This coupling effect is handled by isolating the loudspeaker from the surface. Sometimes, this coupling is desired. For example, sub-woofers are usually placed directly on the floor or floor of the stage. By doing so, their lowest bass frequencies are increased in power by their interaction with the stage floor. Professional PA system sub-woofers are quite often designed to be coupled to the floor in this way. 2) “Coupling” also means the way in which an audio signal is transferred from one device to the next device or from one circuit to the next circuit. Coupling in this case describes the electronic wiring and circuitry used to transfer the signal; called a coupling circuit.
CPPM: See Content Protection for Pre-recorded Media.
CPRM: See CONTENT PROTECTION FOR RECORDABLE MEDIA.
cps: An abbreviation for cycles per second. The original unit of frequency. The unit “Hertz” is now used to denote frequency. For example, 100 cycles per second (cps) is usually written as 100 Hz (Hertz). Named after Heinrich Rudolf Hertz, (1857-1894), a German physicist.
CRACK: In a snare drum, the sharp attack of the stick on the head enhanced by a boost around 5 to 10 KHz.
CRANK: 1) Early movie cameramen and projectionists would turn a crank to move the film through the motion picture camera or projector. Thus the term “crank up the projector”. To “undercrank” or “overcrank” is to make the speed of the camera or projector go slower or faster than its normal rated speed. 2) The term “crank it up” means to start any mechanical or electronic device; to turn it on. Like old-time automobiles were started by turning a crank.
Cr Cb: See Y, Cr, Cb.
CREATE A LARGE LISTENING AREA: In mixing for stereo or surround sound music or film sound, mixing the sounds in such a way that they fill up the room and project out into the room so that even those listeners sitting off to the side (not directly seated between the loudspeakers) hear a wide sound presentation as well. This effectively makes the listening area of the room “larger”.
CREDITS: 1) At the end of a film or video, the listings of names and businesses who contributed to its production or distribution. It’s a list of who deserves “credit” (recognition) for having assisted in the production of the product. 2) On a music release packaging, the listing of names and businesses who played a part in producing or helping to produce the final product and its distribution. Often thanks is stated.
CRESTRON: A brand of computerised control that can operate many different types of equipment such as a TV, CD player, video deck, DVD, satellite receiver, etc. It can be used for multiple-room installations of audio and video systems.
CRIMP LUGS: See CONNECTORS TYPES OF.
CRISP: A term used to describe a quality of sound. Extended high-frequency response which creates a sound as if there is just a bit too much high treble EQ added to the sound (in mixing or playback over an audio system). Said also when sound, especially over PA speakers, is very clear - such as the high sounding drums, cymbals, etc.
CRITICAL BAND: There are certain bands of frequencies which the human ear does not pick up as well as other frequencies. Also, there are frequency ranges in which it is harder for an audience to differentiate between two sounds. (One sound masks another if the two are very close in frequency. The sound that is even slightly louder will tend to mask the other similar sound.) There are 24 of these points within the audible frequency spectrum. This datum is important - whether or not true for all persons (especially those who have done hearing drills) - because the audio industry uses this datum about “critical bands” in the application of compression (reducing digital recording information). The concept of critical bands is used for all types of audio compression. (See COMPRESSION3, PERCEPTUAL CODING, AUDITORY MASKING for more information.)
CRITICAL DISTANCE: The point, a distance away from the sound source, where the direct sound and the reverberant sound are equal in volume. It’s the area in the room when one hears the sound directly from the loudspeakers just as loud as their sound also reflecting off the walls, ceiling, etc.
CRL: An abbreviation for Certificate Revocation List. This is a blacklist of types of equipment that are expressly unauthorised to receive high definition video signals. This is tied into the copy protection methods developed to prevent piracy of HD video programmes. Examples of equipment on the CRL list would be any recording device that could receive and store the full, uncompressed high definition video signal. There is more data on this at HDCP (High-bandwidth Digital Content Protection.)
CROSSFADE: A gradual volume shift from one sound source or group of sources to another. This is usually done using the volume slides (faders) of a mixboard.
CROSSOVER: An electronic device used to separate the audio signal into two or more separate frequency bands. It is frequently used with speaker systems.
CR-1, CR-1A, CR-2, CR-2A: See NAKAMICHI.
CrO2 : On some cassette decks and cassette tapes you see the symbol CrO2 which is just the chemical formula for chrome tape (Cr = chromium and O2 = oxygen). Chrome is a type of metal particle used to record sound on some types of cassette tapes. It is the same setting as “SX (II)” mentioned in the NAKAMICHI CASSETTE DECK glossary entry. The Standard Tech Cassette Decks used in org course rooms don’t have this term on them, but if you are listening to an LRH cassette tape at home on a cassette deck that does, you want to press the button which says METAL (on some cassette decks the “metal” and CrO2 settings are combined on the same button position in which case select the METAL, CrO2 position).
CRUNCH GUITAR: An electric guitar style where powerful distorted rock-type chords are played but the player mainly hits at the instrument’s lower (bass) strings while muting their ability to sustain at the same time. The individual chord hits sort of “crunch” (are not allowed to extend or sustain). The playing is also done very percussively to directly add to the power of the song’s beat and emotional feel.
CRUSH TRACK: This is a mixing trick for music and voice. One first mixes the music or voice then additionally routes it to another mixboard channel. With this additional channel, the sound is mixed a second time. Because the two mixes are on separate mixboard channels, they still exist independently and can be blended together. The second mix, before it is blended into the first, is sent to a compressor set very high so as to compress the sound heavily. It literally “crushes” the sound. Crushed sound has an increase in bass and high treble frequencies and often such frequencies are added in more by the Mixer using an EQ in addition to the compression. This crushed sound is then blended back into the originally mixed sound. By adding just a bit of the “crushed” sound, sometimes the first sound (first mix) can be given more body and presence. The sound can be made to pop out of the mix just a bit.
CRT: See CATHODE RAY TUBE.
CRT PROJECTOR (video): An analogue video projector. They have three projection lenses, called “guns”, which project the red, green and blue hues of the image separately onto the viewing screen.
CRYPTO: Computer software that does the scrambling required to encrypt computer information. It also does other functions such as providing “digital signatures” which are a computer user’s way to authenticate oneself to others and others to oneself.
CRYPTOGRAPHY: The science and methods of protecting information by way of codes. In the world of computers this is a very big deal because the US Government has, for many years, prevented private individuals from fully encrypting the information they send via computer. What coding schemes the government has “allowed” have only been those it can still access. Government agencies, principally the NSA (National Security Agency, who constantly monitors all forms of communication for national “security”) has fought to prevent private citizens from having advanced encryption which would prevent the agency’s ability to access such. However, public cryptography is now available for domestic (not international) messages.
CRYSTAL OSCILLATOR: Every computer has a crystal oscillator inside its circuitry. It is somewhat similar to the type of quartz crystal used in the digital watch you wear on your wrist. Quartz crystal is a mineral (a type of rock). The atoms and molecules in a quartz crystal are very orderly aligned. This gives crystals their unique physical structure. When a flow of electrical current is hooked up to a crystal, its physical structure vibrates - and it does so very orderly, very evenly. The vibrations are at a exact, unchanging, precise rate. Due to this phenomenon, small quartz crystals are often used in electronics and computer technology. When the crystal is supplied a tiny amount of electricity, its precisely timed vibrations can be used to tell time with extreme accuracy. The quartz crystal is actually the stable datum in a digital watch or clock. In computers they are a stable datum as well. This enables all the computer’s many features and functions to operate together in a coordinated manner - all based on the same timing reference. “Oscillate” means to go back and forth - to vibrate. An “oscillator” generates such vibrations. The full name for a crystal, when used in electronics and computer systems as described above, is “crystal oscillator”. The crystal oscillator’s vibrations are used to compute seconds, minutes, hours, etc. (So many vibrations = one second, one minute, one hour, etc.) It’s the same inside the computer. The computer uses the crystal oscillator as an exact reference, just like your watch uses crystal vibrations as a reference timing signal. In a computer, the vibrations are evenly paced pulses that determine the computer’s speed. These vibrations can be called “clock ticks” or “clocking”. During each clock tick, the computer actually does something - it does some form of work (computer processing). However, in-between each clock tick, the computer does nothing. The more clock ticks, the faster the computer will run for the simple reason that there are more ticks, and when there is a tick, the computer performs work. Between each tick, no work is done internally within the computer. The reason a computer needs a clock at all is to keep all its processing working at the exact same speed at all times. If different functions of the computer were to operate each on their own individual time frame, and at their own speed, things would go haywire. The computer’s processing would not all work together. In computers, the data information and processing must all be at the exact same speed at all times. The more clock ticks per second, the faster the computer will run (do its work). Clocking is also important when hooking one digital device up to another, such as two digital tape recorders. In passing digital data between them, the receiving recorder must know where each “word” starts and stops so it can process it. Clocking enables the words to be passed between the machines, with each machine working in time together. The “clocking signal” is sent, together with the digital data, so the timing of the words can be determined by the receiving device. If not for this feature in digital audiovisual equipment, the audio or video pictures would have distortions or not play at all. Computer clock speed is measured in “Megahertz” (millions of Hertz) or “Gigahertz” (billions of Hertz). When you read the specifications of any computer or computerised device, it will state the number of Megahertz or Gigahertz at which it will operate. That’s its speed. If a computer has a speed rating of “800 Megahertz”, its internal clock is vibrating (“ticking”) at a rate of 800,000,000 times per second; the computer’s internal design is all geared around operating at that speed.
CRYSTAL SEMICONDUCTOR: Name of a company that makes high-quality digital converters in chip form. Their chips are commonly used in audio equipment to convert digital signal to analogue.
CRYSTAL SYNC: A crystal is a piece of quartz that vibrates at a specific frequency when a flow of electricity hits it. (That is why they are used in watches and other timing devices.) Sync is short for synchronisation. The speeds of things such as cameras and sound recorders must be very exact in order for the sound and pictures to be played together. The usual way this is accomplished is with an internal electronic circuit having a crystal-controlled timer. “Crystal Sync” circuits exist in film cameras and sound recorders which make them run at a very exact standard speed that allows them to be synchronised in post production.
C-SPAN: Cable-Satellite Public Affairs Network. C-SPAN is a non-profit public service network that provides live coverage of the U.S. House of Representatives. It delivers around-the-clock programming on cable television systems and satellite. It is supported by the cable television industry and actually consists of several different stations; C-SPAN, C-SPAN2, C-SPAN3, WCSP-FM 90.1 in Washington D.C. (C-SPAN Radio 90), and over the Internet at www.c-span.org.
CSS, CSS 2: Abbreviation for Content Scrambling System, version 2. CSS 2 is a method of encrypting audio content for delivery on DVD discs, but it now goes by a different name: Content Protection for Pre-recorded Media (CPPM). CSS 1 (version 1) was approved at the very inception of DVD-Video discs as a means of preventing disc-to-disc digital copying, BUT in October of 1999 a 16 year old Norwegian boy broke the Content Scrambling System code developed by Panasonic and Toshiba to protect DVD-Video discs from piracy. The teenager then published this information on the Internet. This delayed the release of the DVD-Audio disc as no protection code existed for its music. A more powerful protection code was then developed. The new method was initially called CSS 2 and was completed in December of 1999, but was renamed because the name “CSS” had been tarnished by the teenager’s actions. CPPM is used to protect all types of DVD’s - audio and video.
CUE, CUED, CUED UP: 1) A signal to start or stop an operation or to move to a predetermined point in programme material. When using magnetic recording tape to play back a sound, one has to move the tape to the desired start or end point and it may involve spooling (fast winding) or a reel change. When one has the tape rewound and is ready to play the sound at the push of the machine’s button, it is said to be “cued”. 2) A signal given to a person speaking or acting telling him when to start talking or to do some action. The signal is usually given secretly from the audience’s view. 3) To be ready to move or work. The machine is “cued”, or “cued up”.
CUE BUSS: A feature on an audio mixboard. The “buss” (a pathway down which one or more audio signals can travel) sends music to performers so they can hear the sounds they are making when they play an instrument and-or sing. For example, if one were recording a song in a studio, you might wish to add a new instrument to the song. To do so, you would listen to what has already been recorded by putting on a pair of headphones. While listening, you would play the new instrument along with what you are listening to over the headphones. That way, your new part is in perfect time with those instruments already recorded. The “cue buss” feature of the mix board is what sends, not only the already recorded sounds one is playing along with, but also the sound of the new instrument you are playing. Thus you hear everything blended together in your headphones while you record in front of a microphone in the studio. It’s called “cue” because what the musician is hearing is “cueing” him (telling him, giving him a sign) as to when to start, stop, and what and how to perform his part.
CUE FOIL: A shiny piece of tape with adhesive on one side, having a very thin metallic surface, that is pressed onto a section of audio recording tape at the start or end of a recorded programme. When the tape passes a light installed into a playback machine, the foil reflects the light into an electronic circuit which creates a signal. This signal then “cues” other machines that the programme recorded on the tape is starting or ending.
CUE SHEET: An audiovisual industry term for a track sheet used in mixing a film soundtrack that gives locations of edited sounds on a track-by-track basis, either in film footages or in time code numbers.
CURVE: See EQ curve.
CUT: 1) To decrease the volume of a sound. 2) To decrease the volume of specific frequencies using an equaliser. 3) To precisely separate two pieces of audio recording tape using a razor blade or special scissors so that an edit can be made, or to perform this action with a computerised editing workstation. 4) To precisely separate a piece of film during editing or when assembling the negatives of a film for final production. 5) To stop filming and recording a shot done on a movie or video set. 6) Said of a sound that penetrates or stands out, sometimes harshly so. 7) An individual song on a phonograph or CD or DVD. It comes from the old days of phonograph production where each song was “cut” into a master record from which duplicate copies were sold to consumers. Literally, the grooves on the master were cut into its surface of by a “cutting lathe” - which looks like a giant phonograph player and a whole lot more.
CUT AND PASTE: A feature on computerised audio and video editors that allows the operator to remove select portions of a programme and move it to another location in that same programme. It comes from the old days - when regular typewriters use to be used. Often a typed page would have certain paragraphs cut out by scissors and then it would be moved to another location in the document where it would be taped in place, or stuck with paper glue (paste). Even word processing programmes in computers, such as Microsoft Word, use the terms “cut” and “paste” when moving and removing words or sentences.
CUT AND PRINT: Abbreviated “C&P”. A film or video script is divided into a series of individual scenes (shots) which are filmed in sequence. A shot is repeated until it has been performed and filmed correctly. Each time the shot is done is called a “take” (take 1, take 2, etc.). All departments in the shoot crew work together to create a perfect shot. When this has been achieved, the take is called the “cut and print”. The term “cut and print” is also used when making an audio recording.
CUT-OFF FILTER: A “cut-off filter” is an electronic circuit that prevents the extreme high (treble) or extreme low (bass) audio frequencies from passing through it. In the field of audio, the term “cut-off” means to stop and a “filter” is an electronic circuit that removes certain frequencies while allowing others to pass through. Cut-off filters can be found on each channel of most mixing consoles (mixboards). They are usually activated with a pushbutton. The frequency at which the circuit becomes active is usually pre-determined and built-in by the manufacturer, but on some consoles the cut-off frequency can be varied by turning a knob. Often a mixboard will have two cut-off circuits, one for low frequencies and one for high frequencies. A “cut-off filter” totally prevents passage of the frequencies and another type of filter, a “roll-off filter”, just reduces the frequencies.
CUT SWITCH: Any button or switch that turns off or stops a signal flow. Applies to audio as well as visual production equipment.
CUT THE EVENT (OR SHOW): The question…”Who is going to cut the event?” is sometimes heard. This refers to the Technical Director in the Production Truck at a live event. This is the person who calls the shots (directs which camera’s picture is to be seen by the audience and when) and thereby creates the live edit (“cut”) of the event for the audience in the event hall and for the live satellite broadcast audience.
CVBS: An abbreviation for Composite Video Blanking Synch (signal) and is written next to the input and output connectors which send and receive composite video signals. (See COMPOSITE VIDEO, BLANKING.) Note that CVBS is not the composite picture signal itself, it is only the synch signal. The composite picture signal comes out of another connector and is marked as such on the back of the equipment. Also note that not all video players, TVs and monitors have this synch connection. It is provided by some manufacturers as an extra video synch reference connector.
C-WEIGHTING: (See WEIGHTING.)
CYBERSPACE: The writer, William Gibson, in his novel “Neuromancer” in 1982, envisioned a “virtual-reality network”. The word “cyberspace” comes from a coined Greek word that meant to steer or guide. It is the “guiding” or “steering” of information. Cyberspace is the “universe” of environments, such as the Internet, in which persons interact by means of connected computers. One aspect of “cyberspace” is that communication is possible independent of distance.
CYBERSURFING: See SURF.