Audio-Visual Glossary



“I” or “i”:     1) An abbreviation for “interactive.”

2) You will see this in regards to TV or video picture display quality. It deals with how the lines of resolution are created on a TV screen or by a video projector. Stands for “Interlaced”. (See INTERLACED SCANNING.)


IATSE:   An abbreviation for International Alliance of Theatrical Stage Employees. The IATSE is an international (USA and Canada) organisation of unions representing the various trades involved in the theatre and film industries. The alliance includes more than 850 union locals, both in the United States and Canada. (A “local” is a branch of any union located in a given city.) It has 20 local unions in Hollywood, including those for camera personnel, electricians, costumers, grips, set painters, script supervisors, make-up artists, sound technicians, film laboratory technicians and cartoonists. The IATSE negotiates many of the standard agreements between these various trades and the film and theatre industries.






ICAP:     An abbreviation for Interactive Communicating Application Protocol. ICAP is a compact computer protocol for inter­active television developed by Wink Communications of Alameda, California, for set-top boxes and televisions that lack the hardware for a full browser.


ICON:    An “icon” is a symbol seen on a computer’s screen that, when “pressed” or “clicked” allows a new feature or function of the computer to activate. It comes from a Greek word meaning “likeness”, “image” or “figure.”


i CONTROL:  This is AOL Time Warner’s “Video On Demand” feature for their cable network on digital TV. It gives the home consumer (“I”) full control over what movie videos he or she would like to watch, when they wish to watch them.


IDEAL LISTENING POSITION:       The best seat in a listening environment for listening to music, a film or video’s soundtrack. It is the position that is most evenly seated between the various loudspeakers and at a distance away from the loudspeakers best for the type and size of the speaker as well as the size of the room. In a surround sound listening set-up, often the ideal listening position is a bit closer to the front speakers than the rear loudspeakers. Usually the ideal listening position for stereo music is with one’s head positioned just outside of (further away from the speakers) an equilateral triangle if drawn between the two loudspeakers and the listener. In other words, the listener’s knees would be approximately at the apex (top) of the triangle.




IDE:       Abbreviation for Integrated Device Electronics. This is a commonly used type of computer interface. “IDE” is currently the most popular data connection standard for hard drives and DVD-ROM drives, though any of the computer’s inputs (SCSI, ATAPI-IDE, or external USB connection) can be also used. The IDE connectors are mounted internally on the computer’s circuit boards and do not require an additional circuit card. There are two connectors - one “primary” and one “secondary.” Each IDE cable can connect two devices, with the primary and secondary connectors each accepting two, enabling up to four devices to be interconnected. Note: Though an IDE is sometimes used in place of a SCSI, it can’t interconnect more than 4 devices; where a SCSI can connect up to 7. Another point is that the IDE is less expensive than a SCSI but the SCSI is faster at transferring data. The best choice of which to use depends on its function.


iDVD:     An abbreviation for interactive Digital Versatile Disc. iDVD is an Apple Computer DVD authoring system for home consumer use, put on the consumer market in early 2001. It is bundled with the Mac model G4. (See BUNDLING). iDVD is similar to Apple’s iMovie (a consumer video editing software package) in that it simplifies the editing process for the home consumer. The pro version is the DVD Studio Pro.


ID 0:      Abbreviation for Identification point 0 (zero). ID 0 is the precise starting point for each song or audio track on a compact disc - the “0” point. (See CD ID’s.)


IEC:        International Electrotechnical Commission). A European organisation (headquartered in Geneva, Switzerland) involved in international standardisation within the electrical and electronics fields. The U.S. National Committee for the IEC operates within ANSI (American National Standards Institute).


IEC RECEPTACLE (POWER PLUG):       A type of power cord that plugs into the actual piece of audio or electronics equipment as well as into the wall outlet. It has a specially shaped female plug for the equipment end and the usual plug on the wall end.


IEEE:      (Institute of Electrical and Electronic Engineers). The largest professional organisation for electrical engineers. Primarily concerned with education and standardisation.


IEEE 1394:   (Institute of Electrical and Electronic Engineers). IEEE-1394 - also called “FireWire” and-or “i-link” - is a wire and connector standard classification for transferring digital signals. IEEE 1394 is used with computers. It is also used in some audiovisual equipment. For example, it is being used by the Cable TV industry as the cable (wire) to hook High Definition TV to a consumer’s TV.


IFB:        An abbreviation for Interruptible Foldback. One sees the abbreviation “IFB” on phone line (PL) control stations in virtually every production truck used for live events. This is a feature built into a PL system that allows the Mixer, Producer or other person at the PL control station (usually located in the Truck Audio booth) to talk to a performer who is receiving a foldback signal feed (a “send”) from the mixboard. The musician is receiving a foldback - the music he needs to hear and-or his vocals and the IFB allows that foldback to be “interrupted” so the Mixer, Director, Producer, etc. can talk to the performers through their monitor system.


IFPI:      International Federation of the Phonographic Industry. This is an organisation with many members throughout the music industry. It is still active, despite nominal use of the phonograph in present time. They still work to advance and protect reproduced music.


I-FRAME:      An “Initial-Frame.” A term used in video when MPEG compression is applied. See MPEG for exact description of an I-Frame.


i-LINK:  See FIREWIRE. It’s the same thing.


ILLUSION OF SPACE:        In mixing music for films, in stereo or surround sound, the Mixer creates an illusion of space - meaning that all the sounds within the mix have spatial qualities of dimension, depth, height and width as well as reaching out into the room. The loudspeakers should more or less seem to disappear and the sounds themselves have realistic locations in the listening environment.


IM:  1) An abbreviation for Inter-modulation distortion. (See INTER-MODULATION DISTORTION.)

2) An abbreviation for Internet Modulation. (See INTERNET RADIO.)



1) Any film or video picture displayed.

2) An individual sound in a recording or mix that can be heard as having a specific location and size in relationship to other sounds.


IMAGE STABILISER:  Some digital video cameras and binoculars have the ability to electronically (digitally) “stabilise” the image being viewed. For example, holding a pair of binoculars while viewing a very distant object usually has some shaking of the image. Image stabilisation is a feature on some of these devices that aids in making what one is viewing more steady.


IMAGING:     1) The measure of a loudspeaker system’s ability to present stable and specific images of individual voices, instruments, sound effects, etc. when the soundtrack is played.

2) In a mix, each “image” (individual sound) has a space of its own relative to the other sounds and the each can be heard to appear not just from the loudspeaker itself but from above it, to the outside, behind it, and all around. The sounds are reproduced correctly in terms of their relative sizes and spatial relationships to each other.


I-MAX:   The largest type of cinema film used for movie presentations. Each frame of the film shot in the I-Max camera and projected using an I-Max projector uses three full 70mm film frames. Special projection equipment transports the film and projects it onto an extremely large screen. Special theatres exist which have huge dome-type screens behind which are many channels of speakers to play these films. They are called I-MAX theatres and only play I-MAX films. I-MAX films are not usually Hollywood type films but more towards documentary types. These films usually emphasise motion and large expanses of space which greatly move audience involvement and emotional response. The picture is literally all around one.


iMOVIE: (See Apple iMovie.)


IMPACT:       This is a term used in the SADiE digital audio computer manual. The SADiE audio computer has a limiter built into it. Most limiters have adjustable controls that can be set by the operator. One of these settings for the SADiE limiter adjusts what SADiE calls “impact.” It is actually the “attack” - how rapidly the limiter will react to a peak volume of incoming sound. For example, one would set the attack time (“impact”) of the limiter differently if one were recording a snare drum than if a violin were being recorded. On the SADiE, the higher the “impact” number is set, the faster the limiter will react to peaks in sound volume.


IMPEDANCE:       The total opposition a circuit, cable or component offers to alternating current. It includes both resistance and reactance and it generally expressed in ohms.


IMPEDANCE MATCHING TRANSFORMER:   (See IMPEDANCE.) A transformer that changes the impedance of an electronic equipment’s signal output so it matches impedance of an input of another piece of equipment it is sending its signal to. Such a transformer can also change the voltage (strength, power) of the signal as well, depending upon its type.


IMPORTING:       In computers, “importing” means to accept some data - to “import,” from another source or location. “Importing” may require that some conversion process takes place to get the data from one computer to be acceptable to another computer or computerised device.


IMPULSE:     An abrupt, extremely brief burst of signal energy; a transient. There are certain tests regarding sound which use impulses of sound.


IMPULSE NOISE:        Unwanted ticking or popping sounds or ticks. They are very brief “impulses” of noise, such as the loud pops coming from the surface of a phonograph record.


IMPULSE TEST:   The use of a sudden loud “pop” sound (an “impulse”) in a room so that audio testing equipment can measure the amount of reflection of that sound within the room. Such a test can tell one much about the acoustical properties of a room, especially as regards its amount of reflected sound off its various surfaces.




INDUCTION:               The phenomena of a voltage, magnetic field or electrostatic charge being produced in an object by lines of force from the source of such fields without the two touching.


INDUCTOR:  This is a coil that can store energy and thereby oppose unwanted changes in current. Inductors are used inside electronic equipment, on circuit boards, etc. Inductors are also used inside loudspeaker crossovers because the principle upon which they work helps to route the correct audio frequencies to the correct speakers for those frequencies.        


INFINITE BAFFLE:     A term used in loudspeaker design. This is a fancy name for the front wood surface in a speaker cabinet box in which the speakers themselves are mounted. The front panel prevents the sound which comes out from the front of the speaker from going back around to its back. (There is sound that comes from the back of the speaker inside the cabinet and that “rear” sound, if it combines with the sounds from the front, harms the clarity of the audio. The infinite baffle is designed to handle this.) It is called a baffle because it “baffles the sound” (prevents sound). And it is called “infinite” because there is not one hole allowed anywhere in its surface - it has theoretically infinite blockage of sound leakage from inside the cabinet to the outside, though of course in practice some sound does leak through.


INFINITY:    A loudspeaker manufacturer in Chatsworth California now owned by the Harmon Group. It was originally founded by Arnie Nudell, whose new company is Genesis Technologies, a speaker manufacturer in Colorado.


INFOMERCIAL:   A “long-form” broadcast commercial (longer than the “short-form” 30 and 60 second ads) that provides an extensive amount of information and come-on for a product. Infomercials are commonly 30 minutes in length and are used to market a product on television.


INFORMATION:  1) The audio or video content in an audiovisual product. Anything seen, anything heard on such a product.

2) What got recorded. “Not much information was on the tape.”

3) The audio or video signal routed to any other location or other piece of equipment. “We received the information from the event production truck and projected it on the main screen in the auditorium.”

4) Additional data on a CD or DVD included digitally such as the name and title of each song which can then be seen in the display screen of a player or over a TV screen. “The title information is included on the disc itself.”


“INFOTAINMENT”:    The combining of entertainment and information - educational, informational and entertainment on multimedia formats such as DVD’s and CD’s or the Internet.


INFRARED:   The prefix “infra-” comes from the Latin word meaning “below” and red is the lowest frequency of light that can be perceived by the human eye. The frequency of “infrared” light is just below the band of visible frequencies, thus it is a type of light that is invisible to the human eye. Infrared frequencies are used by wireless remote controls to send signals to the components they control.


INFRASONIC:      The prefix “infra-” comes from the Latin word meaning “below” and sonic means “of or concerning sound”. “Infrasonic” frequencies are below (lower in pitch than) the range of audible frequencies. Some audio systems can actually produce “sounds” which are lower in pitch than the human ear can perceive. For example, although inaudible, the infrasonic range from 15 - 20 Hz can be felt physically if strongly reproduced.  


INFRASONIC FILTER:       A filter designed to remove extremely low frequency noise, usually between 8 Hz and 25 Hz or lower, from the audio signal. Such a filter can prevent very low sounds from passing on to a loudspeaker system and the listener(s). Sometimes phonograph records are warped slightly. If there is a powerful subwoofer as part of the loudspeaker system, then an infrasonic filter can be switched in which will help get rid of the very low frequency bass sounds the warp creates every time that area of the record is played.


INI FILES:    This is a term used in the SADiE digital audio computer manual. Abbreviation for Initialisation Files. To “initialise” means to prepare a piece of equipment, computer, printer, floppy disc, etc. so as to ready it for use. In the Microsoft Windows operating system, ini files contain information about the initial set-ups of the computer such as the factory pre-set information the computer uses to set itself up to be used. Examples of settings in an ini file are word processing instructions for the computer itself. These include fonts, page margins and line spacing. In the SADiE system, ini files exist for every individual function. They are instructions to the computer installed at the manufacturer. Examples include ini files for SADiE’s playlist display, mixer setup, etc.


INITIAL-FRAME: An “I-Frame”. A term used in video when MPEG compression is applied. (See MPEG for exact description of an I-Frame.)


INITIALISE: The word “initialise” means the action done first (initially), before any other action in a sequence. To “initialise” means to prepare a piece of equipment, computer, printer, floppy disc, etc. so as to ready it for use. Initialising clears the equipment (or floppy disc) of any old information stored in it and prepares it for a new task. When a floppy disc is being formatted by a computer, the first thing it does is to “initialise” the disc.


IN-LINE:       Anything that is in a row. For example, an “in-line” loudspeaker is a speaker cabinet with all its internal individual loudspeakers in a vertical row.


IN-PHASE:    The term “in-phase” is one of the most important as regards audio and audiovisual equipment. For example, when a drum plays, the individual loudspeaker cones should all move in the same direction - and they will, if they are wired up inside their cabinet correctly. In such a system, the woofers in each cabinet should both move OUT at the same time. If one cabinet’s woofer speaker cone “sucks in” when the drum is played and the other cabinet’s “pushes out”, then some of the drum’s sound will be cancelled out. The two loudspeakers’ “sound pressures” - meaning their “vibrations” - are opposite. They are not going back and forth in unison. The two speakers are “out of phase”. They should be “in phase”. Electronic audio equipment can also be connected in or out of phase. They have to be hooked up correctly to be in phase. Sounds sound best IN PHASE, they sound dead and dull and lack bass and ambience when OUT OF PHASE.


INPUT:  The place that the audio or video signal goes into a piece of equipment. Examples are where the microphone signal or tape machine signal goes into the mix board. It’s a connection from signal source.


INPUT GAIN:       1) The name of a volume control that is specifically for adjusting the volume of the signal coming into a mixboard or other electronics device. It adjusts the volume coming in via the equipment’s input. It is used so that the signal will not be so weak that one can hear the electronic noise inherent in the equipment’s circuitry, but not made so strong that the circuitry will distort.

2) The amount of strength-volume-loudness of any signal entering a piece of audiovisual equipment - audio or video. Gain = volume.


INPUT MODULE: The first stages (the first electronic circuits) within a mixboard or other audiovisual electronics component that accepts and controls the sound (signal).


INSERT:        1) To place a sound into a mix, or picture into an edit. “Insert the sound of a gun going off in the background right at that point in the film’s soundtrack.” “The video editor did an insert, so now there is a picture of an American flag briefly before cutting to the titles.”

2) A port or connection on an audio mixboard (or other audiovisual device) that gives one the ability to take an audio signal from the device or mixboard, feed it out to an external device and then accept the signal back again, to be blended into the unit’s original sound.


INSERT EDITING:      A method of editing together an audio or visual product by placing (inserting) new material one bit after another to create the full length of the programme. This was how video editing used to be done, before computers were used. One would just keep adding footage to a blank tape to build up the show. It is called insert editing because you can’t actually record and stop and record and stop a blank videotape. It is a technical point regarding a video machine and how they work. If you took a blank videotape and upon it recorded 10 seconds of pictures then stopped the tape, you would not be able to add a second bit of footage without creating a huge “glitch” of static on the tape between the two shots. However, there is a way to prepare the blank tape so you can keep recording onto it. One has to prerecord some sort of video signal on the tape. That way the video recorder has something on the tape it can lock onto and track with. It has a “reference” so to speak. Therefore, one is “inserting” new pictures into that pre-recorded signal you put on the blank tape. That’s really why it is called “insert editing”. When computers are used for editing, one can see the edit digitally right on the screen - there is no need to record to any video tape until the whole thing is done and the entire tape can just be run without stopping and starting.


INSULATOR:        A substance such as glass, air, plastic, etc. which will (for all practical purposes) not conduct electricity.


INTEGRATED AMPLIFIER:       An audio component that performs the functions of both a preamplifier and a power amplifier. The two are combined (“integrated”) into one chassis. It combines pre-amplifier elements (such as inputs to plug in CD players, tape recorders, DVD players, radios; switches to select between them; volume controls; etc.) and amplifiers for loudspeakers and headphones in a single unit. Integrated amplifiers commonly are part of home stereo or surround sound systems.


INTEGRATED CIRCUIT:    Abbreviated IC. An IC is a miniature circuit in a small, sealed housing which is usually connected to a printed circuit board. Inside a computer or almost any electronic equipment are devices called integrated circuits - also called “microchips”, “chips” “microprocessors”, etc. An integrated circuit has an incredible amount of electronic functions that have been condensed down to a super small size.




INTERACTIVE, INTERACTIVE TV, INTERACTIVE DVD, INTERACTIVE CD:        Able to interact with the user. Various new CD’s, DVD’s and TV shows are interactive, meaning the user can actually involve himself with the programme directly, not just watch or listen. For example, there are TV game shows now where viewers can participate directly in the game. Some CD’s are called “CD-I” (stands for “Interactive CD”). And DVD’s have videos or video games on them which allow the user to select how he would like the show to progress and end. (Plot changes can be prompted by the viewer and different endings created.) Certain TV programmes are interactive and televisions so equipped can be hooked up for interactive TV. Interactive TV programming is becoming more and more used by broadcasters and their clients.




INTERCONNECTS:     Cables (wires) used to connect audiovisual components. They “interconnect” such. Interconnects specifically refer, not to the wire used to hook up loudspeakers to an amplifier, but to the wires used to hook up the equipment that comes before the loudspeaker amplifier. This includes such gear as CD players, DVD players, tape recorders, etc. There are “audio interconnects” and “video interconnects”. Interconnects come in different configurations, but they are all shielded to prevent interference.


INTERFACE, INTERFACES:      “Interface” means “to bring together”, “to connect”. Interfaces are required to connect up computers and computerised audiovisual equipment so as to allow one piece of gear to operate in conjunction with another, and to help the user produce products using them. An interface usually consists of a wire or wires that run from one piece of equipment to another. It is connectors, the wire and connection points on the equipment itself. An interface also includes some electronic circuitry that enables the computerised equipment in the interface to “talk” to each other via these wires and connectors. ]


INTERFACE types of: The following is a listing of many of the more well known and commonly used connections and interfaces used in audiovisual production and equipment.



Most technical terms used below are separately listed in this glossary.



Interface standard set by the Audio Engineering Society and the European Broadcast Union in 1985 and updated in 1992. Requires an XLR connector. (See XLR CONNECTOR.) Includes two different wiring schemes. The first is called “single wire”, which runs two channels of audio on one XLR connector and “dual wire”, which takes a pair of XLR connectors to pass a stereo digital AES, EBU signal. The dual wire AES, EBU can also be made to pass 8 channels of 24 bit, 96 kilohertz audio. In the back of professional audiovisual equipment, as well as in the back of consumer DVD video players and many CD players, will be found a connector labelled “AES, EBU”, in addition to other types of digital connectors that are different from the AES, EBU standard. It is a good way to hook up different digital audiovisual equipment together.



Same as above (AES, EBU standard for transmission of AES3 data) but on a coaxial cable. Uses a BNC connector as its standard. Is liked by video engineers and video facilities as they like co-axial and BNC connectors. Otherwise the same as AES3, which uses XLR.



Advanced SCSI Programming Interface. The term “SCSI” stands for Small Computer Systems Interface. ASPI is computer software that can be used to assist digital audio equipment that uses SCSI to send and receive data. ASPI is an interface. It is the software a user uses to programme and activate a SCSI data flow between different computer equipment. ASPI and SCSI are used for high quality transfers of digital audio signals between SCSI equipment. See glossary entry ASPI for more information.



An abbreviation for Advanced Technology Attachment. This is the American National Standards Institute’s (ANSI) official name for the computer disc drive commonly known as Integrated Device Electronics (IDE).



Advanced Technology Attachment Adapter. This is a type of connection that anyone can purchase to load music onto a recordable CD using a personal computer or computerised device. The adapter allows one to hook up a computer to load things like music into it without having to buy and install more expensive interface electronics.



Stands for Advanced Technology Attachment PC Interface to Integrated Device Electronics. This is a connection to and from a personal computer or recordable CD device for recording one’s own CD’s. The ATA adapter is used because it allows one’s PC to interface with IDE electronics and it costs less than buying and installing a whole separate package of interface electronics.



The connection on the backs of various digital audiovisual equipment that shows the connection point to plug into to receive or send digital audio on a single wire. It is a type of serial digital interface (SDI) connector. The Dolby and DTS surround sound signals are PCM bit stream signals and are accessed via this connection point.



Co-axial cable has two conductors. One single solid wire positioned in the centre of the cable surrounded by a non-conductive material and the second made of braided metal 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”. There are over 50 different grades of co-axial that are designated by letters and numbers. For example, 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 technical personnel can be assured that the wire is exactly what the numbers designate and that it has no special or unusual qualities.



The “CVBS” connector can be found on the back of some brands of video recorders and playbacks. CVBS is an abbreviation for Composite Video Blanking Synch (signal) and is written by the input and output connectors that send and receive composite video signals. 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.



This is the cable, connectors and electronics that allow a CD transport to be hooked up to a D to A converter. Also used to connect an A to D converter to a recorder such as a DAT machine. Transmits the PCM bit stream from one device to another. “Digital Interconnect” includes S/PDIF, SCSI, AES, EBU and SDIF connections.



Enhanced Intelligent Drive Electronics. Personal computers have this type of connection point for use in hooking up to different pieces of computer equipment and transferring information. It is not the best connection to use. Much preferred, and especially for audiovisual computer information is a connecting point called “SCSI” (pronounced “skuzzy”). SCSI means Small Computer Systems Interface. EIDE is less expensive than SCSI, but it is also slower in its operation.



High Definition TV inputs and outputs for computers have their own separate outputs on the backs of the digital audiovisual equipment that can handle HDTV signals. These are multi-in connections that have little screw-down ends to secure them to the equipment.



A connector seen on the backsides of some DVD players, VCR’s and other video equipment. It stands for Horizontal or Vertical and is an extra connection point for the picture synch signal put on some brands of video players, monitors and TV’s. Note that all manufacturers don’t include this connector and the extra H/V connection is not required to get a stable picture. It is just an additional accessory that can be used to output a video reference signal. Uses a BNC connector.



Integrated Device Electronics. “IDE” is currently the most popular data connection standard for hard drives and DVD-ROM drives, though any of the computer’s inputs (SCSI, ATAPI-IDE, or external USB connection) can be used for this. IDE connectors are mounted internally on the computer’s circuit boards and do not require an additional circuit card. There are two connectors - one “primary” and one “secondary”. Each IDE cable can connect two devices, with the primary and secondary connectors each accepting two, enabling up to four devices to be interconnected.

Note: Though an IDE is sometimes used in place of a SCSI, it can’t interconnect more than 4 devices; where a SCSI can connect up to 7. Another point is that the IDE is less expensive than a SCSI but the SCSI is faster at transferring data. SCSI is preferred when making a high quality music CD on a recordable disc.



“FireWire” is used for interconnecting computers and computerised equipment. Developed by Apple and Texas Instruments. HDTV sets can use FireWire Digital TV cable service at High Definition quality. Its technical specification number is IEEE-1394 and it is often referred to as such. It is intended to replace Apple Desktop Bus (ADB) and SCSI. FireWire supports automatic configuration ("plug and play") and hot plugging (changing peripheral devices while running). You want this type of interface connection on any new High Definition

TV purchased for best hook-up and for eventual interactive use.



See IEEE 1394 (FIREWIRE) above. It’s the same thing.



(Multi-channel Audio Digital Interconnect) AES standard for the interconnection of 56-channel digital audio signals between audio equipment such as mixboards and multi-channel recorders. MADI is the multi-track version of AES, EBU, though much faster as it is handling many more channels of audio. Uses a single BNC video-quality co-axial cable or a fibre optic cable to carry up to 56 channels of audio with a maximum of 24-bit samples.



Abbreviation Myryad Link. Myryad (not myriad) is a brand name of digital A.V. equipment. “My-Link” is their remote control hook-up that uses a pair of RCA connectors installed in Myryad A.V. equipment to send commands to it. This brand of remote can be used with this specific brand of equipment and can have cable lengths of up to 250 feet. Thus, many different Myryad brand units in many different rooms can be controlled by one remote. There is no audio sent over the controlling wires, just a remote control code called “RC-5”.



This type of digital audio input or output is used to transmit or receive the PCM bit stream. A co-axial cable and an RCA phono-type connector are usually used. This is actually an S/PDIF connection and may also be found as the digital connection for Dolby and DTS digital signal on DVD players and AV receivers, which are actually S/PDIF as well.



Red Green Blue”. These are the connectors that are for the colour signals of a picture. The RGB signal is the highest quality type of component video signal. It separately carries each of the 3 primary colours with the full information of each of these carried over a separate wire. RGB signals are always on separate wires from the luminance (Y) signal which is carried over a fourth wire in the RGB component colour system. This type of colour is even higher quality than the Y, Cr, Cb or Y, Pr, Pb type component signals, where only the red and blue information is carried by separate wires from one piece of equipment to another. (The green signal is electronically created by circuits inside televisions, TV monitors, video projectors, etc.) Much home consumer and even some professional video equipment does not have full RGB capability. This does not mean that the component Y Cr Cb, Y Pr Pb picture looks bad, but RGB is the highest quality.



RS = Reference Standard. The EIA (Electronics Industry Association) standard serial interface used on most personal computers. A format widely supported for bi-directional data transfer at low to moderate digital data rates. The most common interface method used to connect personal computers with peripheral hardware and instruments. Use is restricted to one peripheral at a time and short cable lengths. The standard originally called for DB-25 connectors, but now allows the smaller DB-9 version.



RS = Reference Standard. The standard adopted in 1978 by the Electronics Industry Association as: EIA-422-A. A balanced line twisted-pair standard for all long distance computer interconnections (up to 3300 ft). A high-speed serial communication port allows data to be transferred to and from an external computer at a very high rate (500K baud).



(Small Computer Systems Interface) A connector on PC’s and digital audio equipment involved with recording one-off CD’s and exabyte. Makes excellent copies and is actually the type of connection which is required when making high quality masters for CD and DVD replication.



Serial Digital Interface. A computer interface in which data is passed over a single line, one bit at a time. The MIDI interface is an example of a serial interface, as are the connections in various different pieces of digital video equipment. For example, the 601 video standard uses a serial digital interface.



(Sony Digital Interface Format, 2 channel audio). Sony professional digital audio interface utilising three BNC connectors, one for audio channel 1, one for audio channel 2, and a separate connector for word synchronisation (timing signal) - common to both channels. Originally developed for CD mastering and multi-channel recording equipment. All interconnection is done using unbalanced 75 ohm co-axial cable of the exact same length (to preserve synchronisation). Not intended for long distances.



Sony Philips Digital Interface Format is the so-called "consumer format” of hooking up digital equipment and transferring digital signals. It uses one wire that looks like a standard RCA connector and cable, but, in fact, usually 75 ohm connectors and cables (video cable) are recommended by manufacturers. However, here at Gold, best success has been to use certain top quality audiophile grade interconnect wiring such as Monster M1500 or Harmonic Technologies “Pro Silway 9” interconnect. Better digital audio equipment will usually have an AES, EBU (XLR) connection point for digital data and an RCA connector for S/PDIF. (Testing should be done with any piece of equipment to see which sounds the best as sometimes the S/PDIF will sound better than the AES, EBU.) While S/PDIF was originally stated to be a “consumer format” it is often found on professional digital gear too.



See Y/C below.



Abbreviation for Tascam Digital Interface. Uses a 25 pin connector to send and receive 8 channels of digital audio and a “word clock” signal. (See WORD CLOCK) Used mainly with Tascam’s 8 channel digital audio recorders, such as the DA-88 and DA-98 models.



Stands for Type Of Service LINK and means it is the connection used to transmit digital audio information on fibre optic cable - it is a fibre optic type of service link. A type of optical output and input for transmitting digital audio. It uses optic-optic cable and is regarded as inferior to coaxial digital connections, though Toslink connections can be found on many home and professional audio digital devices. A Toslink input on some consumer audio and home theatre equipment can handle sampling rates from 32 to 96 kHz and up to 24 bits, as can coaxial connections, but other types of optical inputs cannot. “Toslink” is a generic name for this type of connection.



An abbreviation for the Universal Serial Bus in computers and computerised equipment. A connection point (connector) on a computer for hooking up to other computerised devices. “Universal” is a specification meaning that technical personnel can be assured that the connector is exactly what the numbers designate and that it has no special or unusual qualities. “Serial” means that the digital information travels as a series of digital bits - on only one path and in one direction at a time. A “bus” is a pathway down which one or more signals can travel. A “USB” connection is commonly used with personal computers, to connect such things as CD-ROM drives, modems, printers, mice and keyboards. By using the USB connections in each piece of equipment, many individual things can be connected to a PC - up to 127 of them at once!



A connector on the back of many different brands of home consumer video equipment such as DVD players, VCRs and TV’s that is the connection point for the luminance (brightness) part of the video signal. This connector must be used along with and in addition to the connectors for colour signals. An RCA phono-type connector is usually used for the Y signal and it goes along with the connectors used for the colour parts of the picture - “Y, Cr, Cb” or “Y, Pr, Pb” in these types of component video systems.



A “Y/C” cable is the wire that must be used in order to play Super VHS video information. Such a connection exists on DVD players too. This is the only way to view true Super VHS. If a Y/C connector and wire is not used, you don’t have Super VHS quality pictures. Y/C is a video signal interconnect system that keeps the luminance (Y) and chrominance (C) signals separate and is found on Super VHS videocassette recorders and players and DVD players. Note: The better DVD players usually also have component (Y, Cr, Cb or Y, Pr, Pb) signals which are even higher quality than the Super VHS Y/C signal. A 4-pin mini DIN connector is used.


Y, Cr, Cb

The component colour video standard for non-broadcast equipment, such as DVD players and VCRs. “Y” is the symbol for “luminance” (brightness), “C” means “colour”, “r” means “red” and “b” means “blue”.


Y, Pr, Pb

The component colour video standard for Digital Television (DTV) broadcasting and receiving equipment, including the television or satellite equipment used to send the signal and the TVs, video monitors and recording equipment used to receive it. “Y” is the symbol for “luminance” (brightness), “P” means “picture”, “r” means “red” and “b” means “blue”. See the entry at Y, Pr, Pb for a detailed definition. Compare Y, Cr, Cb, RGB.



“Y” = luminance and “U” and “V” are the symbols used to indicate colour signals. (“U” and “V” may have originated from a European standard.) YUV inputs and outputs are designated on some brands of video equipment to show that they are component video systems. Each has its own separate input and output, i.e. the Y, the U and the V are all separate connection points. Other manufacturers of video equipment name their component video signals as “Y, Cr, Cb” or “Y, Pr, Pb” as noted in the entries above.


INTERFERENCE: 1) Interference is any unwanted signal or sound that is interjecting itself into a desired sound and-or video programme. Interference can come from local radio station broadcasting, electric motors running in close proximity to audiovisual wiring, poor quality electricity, etc.

2) Disturbances of an electrical or electromagnetic nature that introduce undesirable responses into other electronic equipment.


INTERLACE SCANNING, INTERLACED DISPLAY:      A process for transmitting and displaying video images, used for conventional TV sets and video projectors. To give a simplified description of interlacing, imagine the screen of a TV set and its picture. That picture is actually made up of very small lines. These lines are created so fast that they look like they are there all the time, but really they are being created by a back and forth motion - a signal is creating them by moving across the screen. A TV or video picture only has so many possible lines of resolution. For an interlaced picture, half of the lines are odd and the other half are even. First the odd lines appear, and then as they disappear, the even lines follow - the even lines are said to be “interlaced” (meaning they pass alternately between where the odd lines were). Therefore, an interlaced picture never has the two sets of lines on the screen at the same time. And therefore, the picture is sort of hazy - and one can easily see the lines without looking very closely. Ideally, all the lines would be presented on the screen at once. That is possible. It is called “progressive-scan.” Progressive scan is where the lines are all on the screen at the same time. They are “painted” on the screen by a single pass of all lines. One therefore sees fewer lines because the lines are so close together, unlike interlaced displays, which have gaps between the lines because only half the potential lines are there at any given time. Progressive scan clearly gives the better picture. (Compare PROGRESSIVE SCANNING.)


INTERLEAVING: “Interleave” means to insert something alternately and regularly between something else. The word actually comes from the action of adding blank pages (leaves) between the printed pages (leaves) of a book or other text. For example, this is sometimes done just after a page comes off of a printing machine so that the fresh ink doesn’t smear.

1) In digital recording, “interleaving” is done to record the digital information on recording tape. The process breaks the information up into very small segments and then interleaves these together. These segments are not recorded in one continuous straight line on the tape. Rather, the parts are “woven” between each other - part A, part C, part B, part D, etc. There is a reason for this. It is important in digital recording that all the parts (“data words”) of the recording are able to be retrieved off tape. If a series of words are missing, then one will hear distortion or nothing at all. To guard against losing any of the digital information due to tape medium imperfections, the digital recorder “interleaves” the digital data going to tape. Each small digital word is put between other words in different areas of the tape. The various words are woven between other words. The words are not in one continuous string. In this way, if any area of the tape is fouled up, then there is very good chance the digital recorder can still find enough information elsewhere on the tape. Because all the parts were not recorded in one linear line of information on the tape no one continuous length of sequential words can be missing. They are woven throughout so there is always a good chance of finding enough digital “words” on the tape to keep the audio playing.

2) Interleaving is also a method for making data retrieval more efficient in computers by rearranging or renumbering the sectors on a hard disc or by splitting a computer’s main memory into sections so that the sectors or sections can be read more rapidly, rather than trying to search linearly on the disc.


INTERMITTENT: A device in a film projector that pulls the film through the gate intermittently at a constant rate of 24 frames per second.  


INTER-MODULATION DISTORTION:    Abbreviated IM. Distortion in this case refers specifically to unwanted changing of the characteristics of a sound by faulty electronic components. “Inter-modulation” is one type of this distortion. It is “inter” because the frequencies in the sound, instead of remaining distinct and uninfluenced by the other parts of the sound signal, get electronically jumbled together and interfere with each other. In other words, they inter (between, among and mutually) modulate (change or alter) each other. Intermodulation distortion is a very harsh, unpleasant sounding type of distortion. It is particularly irritating to listen to because the distorted frequencies that are created are not harmonies of the original non-distorted frequencies of the sound, so the non-distorted and distorted frequencies really are in conflict. This is what makes IM distortion different from Total Harmonic Distortion (THD). IM is quite disharmonious, where as THD is a distortion that occurs at frequencies which are harmonics of the original sound. (That’s why THD doesn’t sound quite so bad as IM distortion and why it is a bit harder to detect by ear.) Neither are acceptable. Both are measurable by meter, and all cables and equipment are tested for such distortion before they are ever let near a production line. However, if a sound engineer suspects that part of his line is distorting he should pull out the Hewlett-Packard 339A Distortion Measurement Set and check it out.










INTERNATIONAL STEERING COMMITTEE (ISC):     A marketing committee that has worked to bring about advancement in digital audio distribution at consumer levels. Specifically, they have worked closely with all major manufacturers to arrive at an agreed upon upgrade over normal music CD’s - the solution being the DVD-Audio disc.


INTERNET:   Abbreviation for International Network. A worldwide computer network available via modem that can connect any user’s computer for the sharing of information. It was originally started by the US Department of Defence in the 1960s to connect universities and research institutions to governmental agencies for data and information flow. This ancestor of the Internet was called the “ARPANET”, standing for the Department of Defence’s Advanced Research Project Agency Network. The Internet now connects all manner of individuals and businesses of all types all around the world. It is accessed via phone lines - including satellite phone lines. Users of the Internet can send each other electronic mail, copy files from one another, etc. Most businesses and corporations, both small and large have Internet addresses for carrying on their commercial transactions. Music, movies, television and other entertainment and news services exist on the Internet. Banking, paying bills and many other activities can all be carried on over the Internet without ever leaving one’s home or office. Unfortunately, there is also a liability to this interconnection of so many people and things in that unscrupulous (criminal) individuals can use it too. Thus, it is very wise to safeguard one’s computer files and communications from such ill-intentioned individuals. Another term that is very frequently heard is “World Wide Web” (also “The Web”, “www” or “W3”). This is a computer programme that organises related information together on the Internet. To gain access to the Internet, most individuals or corporations employ the services of an “Internet Provider”. Internet Providers are companies that have very large computers and programmes that can connect one up to the many services provided via the Internet. It is also possible, with considerable expense of computer equipment, for an individual to directly access the Internet and Web services without going via a provider. Given the equipment, one can directly buy access to the Internet by contacting the telephone company and paying for the use of their lines. There are many abbreviations used on the Internet and in e-mail. You can find a complete listing of these on the Internet itself at




INTERNET EXPLORER:     A Microsoft computer programme that is an easy way to connect the user with any site on the Internet. If you know a site’s address, you just type it in to the Internet Explorer and it connects you to that site. If you don’t know the address, you can type what you do know into the Explorer and it will assist in locating the site. Microsoft’s Internet Explorer programme is available in Windows and Mac versions.




INTERNET MUSIC, INTERNET MUSIC SITE LISTING:     There are various Internet sites that offer consumers vast libraries of music. A listing of such may be found at the end of this definition. Some of these Internet companies are independent (not owned by a major record label or music company). Others are owned and operated by the major record companies themselves. Some sites are legitimate as they offer fair exchange to the artist and record label. Others are actually illegal as they are involved in various forms of rip-off such as paying no royalties. In mid-2001, the major record companies teamed up with different Internet service providers like RealNetworks, RioPort and Yahoo to offer their artists’ music to the Internet service providers’ paying subscribers. Major record labels such as Sony, Universal Music. EMI, AOL Time Warner and BMG, have just started to prepare such Websites. Most of the major label sites are in their formative stages with compression methods, watermarking and copy protection still being worked out. Below is a list of the main Internet music sites. The listing tells which are legal and those that are not or questionable. The listing also gives basic information such as major artists available, if you must pay to listen and-or download the music, etc. There are quite a number of Internet sites that offer music and this listing does not attempt to list them all. More are available all the time over the Internet and some cease operation. You can find individual artists and small record labels with sites. There are also a number of specialised sites that are more or less like radio stations, though they operate over the Internet. The listing below has some of the more popular or interesting of these sites, in addition to “normal” music sites. It should be noted that the music quality from these Internet sites is not up to CD quality level. The music is all processed with MP3 or, more recently, MP4. These are forms of digital compression with the newer MP4 said to be of better fidelity than MP3. Moreover, MP4 includes copy protection and watermarking to help protect artists and music companies, enforce royalty payments, etc. MP4 is sometimes referred to as AAC (Advanced Audio Coding). AAC is also a form of compression used for some music on the Internet. (It is a Dolby development that uses MP4, but also has proprietary protection coding developed by Dolby.) There is another type of digital compression for Internet Music and that is WMA (Windows Media Audio.) WMA is a Microsoft compression format developed to compete with MP3. Music from the Internet can be listened to right at your computer, or “downloaded” and stored in your computer for later repeat listening. There are also devices called “Personal Audio Players” (or “Personal MP3 Players”). These look like small portable radios or portable CD players. Some will accept, in addition to MP3, WMA and AAC (MP4) music. Some personal audio players also play recordable CDs made with MP3 processing. Such a CD will only be at MP3 quality - the sound will not be nearly as good as a normal CD. The better personal audio players will accept MP3, AAC or WMA processed music as well as play MP3 CDs. (See listing below.)



(See MP3, MP3 PLAYER.) An independent Internet site launched in March of 1999 providing music that can be downloaded by consumers to MP3 recording equipment. The music available on is free of charge to anyone. puts music on its site only with the express permission of each artist. Royalty fees are paid by to each artist when their music is downloaded. The site is used as a promotional action and source of advertisement by artists and music companies, in which case they pay for such. offers music from more than 125,000 artists. In December 2000 alone, more than 50 million songs were downloaded from this website.

An Internet site that allows consumers to e-mail a copy of their CDs to the MyPlay website and store them there. The CD’s are then available to listen to wherever the consumer has a computer with Internet access. Consumers could send their entire CD collections to MyPlay and then listen to any of their CDs at any time, right off the Internet. The idea is that one’s entire music library is available any time the MyPlay website is accessed. It’s legal because the consumer is listening to a copy of his own CD that he already purchased. You don’t have to take your entire CD library with you when you leave home, as it is being digitally stored and is available from a computer file on MyPlay’s website.

An email address that offers a subscription service for consumers to download the songs they want. Samples of an artist’s work and-or entire songs may be downloaded.



An independent Internet company, similar to, that offers a wide variety of artists’ music, both well known and not so known, that can be downloaded free from the eMusic website.



An alliance among Bertelsmann Music Group (BMG), EMI and AOL Time Warner that offers a paid subscription service for consumers to download music from the Internet. All three of these major music companies and the artists they represent are available from one Internet site called “”. Musicnet uses the Internet service providers RioPort and RealNetworks to promote and sell the music of the artists on their record labels. Artists available on the site include the Beatles, Madonna, Whitney Houston, Kid Rock, Janet Jackson, Mariah Carey, Radiohead, P. Diddy, Christina Aguilera, OutKast, The Corrs, Faith Hill, Bjork, Aaliyah and many others.

Sony is affiliated with Internet providers Yahoo and RioPort and offers the music of the artists produced and represented by Sony Music such as Jennifer Lopez, Michael Jackson and Barbara Streisand.

Universal Music is now owned by Vivendi, a Paris-based media group that has entered into the US market by purchasing Universal Music. (The U.S. website is in Universal’s name, not Vivendi’s.) Universal is teamed up with Internet service providers RioPort and Yahoo. Popular artists offered include Eminem, Sheryl Crowe, U2, Eve, Limp Bizkit, Tupac and DMX.

An Internet service that allows one to search for the lyrics to any song, and hear the song.

Soundbreak is an Internet radio station located on Sunset Boulevard in West Hollywood. It has live DJs 24 hours a day 7 days per week. In addition to pre-recorded music, Soundbreak also features live band performances and interviews with artists. Broadcasts are done at 16 bit, 44.1 kHz, without compression (CD quality). (See COMPRESSION 3.)

WorldClassRock is an Internet radio station featuring a large library of Rock music as well as commentary. This website attracts listeners who want to hear a wide variety of Rock music - much more than is played by the usual commercial over-the-air radio stations.

Similar to the above Internet radio stations, NetRadio is one of the larger sites broadcasting on the Internet. Their programming is similar to that of a commercial AM or FM over-the-air radio station.

This website provides technical information about Internet radio broadcasting (“Webcasting”) to professionals who want to create an Internet broadcast site. Also included are instructions on how to best receive and listen to Internet radio. Part of the services of “About” include providing better ways for broadcasting music over the Internet, including what type of digital compression can be used to improve the quality and quantity of music available - for example, MP4 instead of MP3. (See COMPRESSION3, MP4, MP3.)

This website provides technical information about Internet radio broadcasting (“Webcasting”) to professionals who want to create an Internet broadcast site. Sonicbox has also developed home consumer receiving equipment for Internet radio.

This website provides technical information about Internet radio broadcasting (“Webcasting”) to professionals who want to create an Internet broadcast site. Afoo has also developed receiving home consumer equipment for Internet radio.

An Internet site that consumers can log onto and download music in the Windows Media Audio format. (See WMA.) WMA is Microsoft’s propriety digital music recording and playback format and recorder-player intended to replace, or at least significantly compete with, MP3. (See MP3 and MP3 PLAYER.)


INTERNET PHONE SERVICE:  A telephone service provided by AOL-Time Warner as part of their Digital TV cable system for home consumers.




INTERNET PROTOCOL TELEPHONY:    Telephone Communications of any type via the Internet - literally being able to make a phone call over one’s Internet phone or cable line. (More data at IP, PROTOCOL .)


INTERNET RADIO:     Literally, “Internet Radio” are radio stations that broadcast over the Internet, as opposed to conventional radio which broadcasts via antennas “over-the-air.” When a broadcast is done over the Internet, it is called a “Webcast.” Internet radio stations are free of charge, and they are not restricted by the U.S. Federal Communications Commission (meaning they do not fall under any regulations or restrictions of the FCC.) Internet Radio stations are easy to receive. You access them just like logging onto any other Internet site. Anyone can establish an Internet radio station providing they have the appropriate computer hardware and software - all of which is readily available. Some electronics companies have developed “Internet radio receivers” that do not require a computer, but can pick up Internet webcasts from the air - just like an AM or FM radio. These receivers must be within the range of specific Webcasting antennas, much like a cell phone has to be within certain areas covered by cell phone antennas. Internet radio is still in its infancy, but growing rapidly. More information on Internet radio and Webcasting can be obtained by contacting the following sites:,, Internet radio is also referred to as “IM” radio. IM is an abbreviation for Internet Modulation. Just like there are conventional over-the-air AM (“Amplitude Modulation”) and FM (“Frequency Modulation”) radio stations, there are also IM (“Internet Modulation”) radio stations. In the case of an Internet radio station, the “carrier wave” being “modulated” might be a communications satellite channel, a telephone wire, fibre optic cable, etc.) While any Internet service could be said to be “IM,” this designation is used specifically for actual live Internet radio webcasts as opposed to the normal exchange of information and commerce on the Web.




INTERNET TELEPHONE:   This is a service provided by cable digital TV companies that allows one to make phone calls right over a cable TV wire. Many home consumers use up their one phone line when they log onto the Internet. Now they can make phone calls over their cable TV line without installation of a second phone line from the telephone company. AOL-Time Warner Cable is the first to offer this service. The same Cable DTV service provides Digital TV, Internet access, interactive TV, and Internet phoning capability.


INTERNET2: The original Internet was never designed to be able to handle its current (and future) traffic flow. Internet2 is the solution being developed by a group of major universities, telecommunications companies, etc. - led by the University of Southern California. It is already linking up the entire United States with optical fibre links, as opposed to the severely overloaded and slow telephone lines being used for the present Internet. The Fujitsu corporation has methods of combining signals that will move down an optical fibre cable as thin as a human hair at up to 1.7 trillion bits per second. That is enough bits, at a super speed, to send 20 million simultaneous phone and Internet calls down just one of these fibres. In terms of audio and video applications, this will enable digital transfers of music and video footage at rates as high as those used for DVD-Video discs. The present practice of processing music and video “to fit on the Internet” (which degrades the quality) will no longer be needed. And access time and send time on Internet2 will be instant - no waiting. In tests already done, two DVD’s worth of audiovisual information was sent in 81 seconds across the United States at these ultra-high digital rates. That’s about 5 hours of programme material. Internet2 will also carry High Definition TV with nearly triple the amount of lines of resolution seen on the TV screen.


INTER-NETWORKING:     This is a coined word for a new technology by the Euphonix company (the maker of the mixboards used for cine, music and video mixing at Gold). It is an alliance of Euphonix, Digidesign, Sonic Solutions, and an Internet specialist firm called Rocket Network to enable audio professionals to control, monitor, share and review their material over local networks and the Internet.


INTERPOLATE, INTERPOLATION: To add or insert a datum, idea, etc. in between other things or parts. It comes from the Latin word meaning “to adorn between.”

1) In digital video, interpolation is the creation of new pixels in the image by a method of mathematically duplicating the values of existing pixels and then replicating them. New pixels are literally made by interpreting other pixels.

2) More broadly in computers and computerised equipment, it is a method of mathematically duplicating the values of existing bits of digital data and then replicating them.


INTER-NEGATIVE:     Abbreviated “IN”. The Film Lab negative element that is made from the Interpositive film element. Both terms are described below. The sequence goes like this: You can’t use the original priceless camera negatives to make final film copies because the original negatives are irreplaceable and would be worn out after a few prints were made from them. Therefore…A) The camera’s negatives are directly copied to another type of negative, called an “Interpositive”. The original negatives have a negative image, just like the photo negatives you get back when you have your own personal camera pictures developed. The direct copy made - Interpositive - is a negative too, but with a positive image. That’s why it is called an interPOSITIVE. It is a negative, not a film print. It is produced by making a DIRECT copy of the original camera negatives. It is exactly the same as the original negatives, only the interpositive has positive images whereas the original’s images are negative. The Interpositive is an “intermediate” step towards ultimately producing a film print. It is a negative, but with a positive image. In order to make a viewable print, you need to have a negative which will produce such. An Inter-postive can’t make a final presentable film print because its images are positive, so any film print would have backward (negative) images. All the colours would be “backwards” too - the whites would be black, and the blacks would be white, etc. Just like still photographs are produced by a “negative negative”, you must have a “negative negative” to produce a movie film. A “negative negative” will produce a “positive print”. Therefore, yet another negative copy is required - this time a direct copy of the Interpositive to yield a negative negative which can be used to make the final film copies - copies you can see. (The way copying film works is that whenever you make a direct copy, the images “reverse” in terms of location and colour in the frame. Therefore you have to go through this two step copying procedure - to end up with a negative that will make a positive final film print.) An Internpostive is the first negative made in this two step procedure. When it is copied, an Inter-negative is produced - and it is that Inter-negative negative which is then used to make final prints for viewing.


INTER-POSITIVE:      Abbreviated “IP”. The Film Lab negative element that is a direct copy of the film’s original camera negatives. The sequence goes like this: You can’t use the original priceless camera negatives to make final film copies because the original negatives are irreplaceable and would be destroyed after a few prints were made from them. Therefore… A) The camera’s negatives are directly copied to another type of negative, called an “Interpositive”. The original negatives have a negative image, just like the photo negatives you get back when you have your own personal camera pictures developed. The direct copy made - Interpositive - is a negative too, but with a positive image. That’s why it is called an inter-POSITIVE. It is a negative, not a film print. Making a DIRECT copy of the original camera negatives produces it. It is exactly the same as the original negatives, only the inter-positive has positive images whereas the original’s images are negative. The Inter-positive is an intermediate step towards ultimately producing a film print that can be presented to an audience. It is a negative, but with a positive image. In order to make the final print that can be viewed by an audience, you need a negative that will produce such. An Interpositive can’t make a film print you can present, because its images are positive, so any film print made from it would have backward (negative) images. All the colours would be “backwards” too - the whites would be black, and the blacks would be white, etc. Just like still photographs are produced by a “negative negative”, you must have a “negative negative” to produce a movie film. A “negative negative” will produce a “positive print”. Therefore, yet another negative copy is required - this time a direct copy of the Interpositive to yield a negative negative which can be used to make the final film copies - this NEXT negative is called the INTER-NEGATIVE and will make release copies. (The way copying film works is that whenever you make a direct copy, the images “reverse” in terms of location and colour in the frame. Therefore you have to go through this two step copying procedure - to end up with a negative that will make a positive final film print.) An Inter-positive is the first negative made in this two-step procedure. When it is copied, an Inter-negative is produced - and it is that Inter-negative which is then used to make final prints for viewing.


INVERSE SQUARE LAW:   Simply stated, the fact that in an un-obstructed area (like an open field) the sound pressure level will drop to half-pressure (minus 6 dB) every time the distance to the sound source is doubled.


INVERTED TITANIUM TWEETER:  A dome-shaped tweeter made of titanium, with the dome is inverted. It looks like a dish and instead of protruding out, the dish curves in. This is a tweeter commonly used in Wilson brand speakers.


INVERTER:   1) A circuit that reverses the phase of a signal.

2) An electrical device that changes direct current into alternating current.


INVOLVEMENT:   The degree to which a reproduced sound draws the listener into the musical performance and evokes an emotional response to it. It is “involving” and enjoyable to listen to as it grabs attention and moves one emotionally. Can be said of any excellent audiovisual product.


I-O:        Abbreviation for input-output. Typically refers to sending information or data signals to and from computers and computerised devices. An I-O has the connection points where this is done.


Iomega PocketZip, Iomega Peerless, Iomega Zip: See MEMORY STORAGE DEVICES.


ION:       An atom that has an excess of electrons (making a negatively charged ion) or a scarcity of electrons (making a positively charged ion).


IP:  1) Stands for Internet Protocol, which is the software and computer operation as regards Internet usage and-or Internet compatibility with and between different systems - such as sending video or music via the Internet.

2) Intellectual Property:     Any property that results from creative thought or work such as a book, a song, etc. An IP can be protected by copyright, trademark or patent.

3) An abbreviation for Inter-positive. (See INTER-POSITIVE.)


IPS:        Short for Inches Per Second, a measurement of how fast recording tape moves past a fixed point (such as the heads in a tape recorder). The faster, the better the quality as there is more tape per unit time of sound = more magnetic tape surface in which to record the sound and from which to play it back.


IR:  Infrared. The prefix “infra-“ comes from the Latin word meaning “below” and red is the lowest frequency of light that can be perceived by the human eye. The frequency of “infrared” light is just below the band of visible frequencies, thus it is a type of light that is invisible to the human eye. IR light signals are commonly used for hand held remote control units such as those which control home consumer audiovisual equipment.


IR REPEATER:     (See IR.) A pair of devices, called an Infra Red sensor and an Infra Red flasher, that together relay IR commands from a hand held remote control to audiovisual components hidden from the remote control’s view - such as a DVD player located behind a cabinet door.


 IRD (INTEGRATED RECEIVER DECODER):        An IRD is the set-top (sits on top of one’s TV or near to it) unit located inside a home consumer’s house. The IRD is not a brand name, it is the technical name for the satellite receiver box that sits in one’s home, near the TV. It allows one to receive the satellite programming one subscribes to.

For more technical information, read on…The IRD performs functions such as demodulation (converting the satellite signal into television signal), encryption decoding, MPEG decoding, and other functions. The IRD also provides audio and data outputs for a variety of potential services, such as data transmission, HDTV, and audio-only programming. The subscriber uses the Digital Satellite System (DSS) through an electronic programme guide and menu functions performed by the IRD.


IRE:       Abbreviation for Institute of Radio Engineers, which is an organisation that sets technical standards in the audiovisual industry. The term “IRE” is usually heard in reference to measuring the brightness of a video picture. The IRE unit of measurement is the agreed-upon industry standard used for the brightness settings of video monitors and cameras. 0 IRE is black. Plus 100 IRE is the correct level for a pure white video picture. (Pure white being the brightest image in a video picture.)


IRON CORE INDUCTOR:  A major part inside a loudspeaker crossover that helps separate out the bass from the treble frequencies and route them to the correct individual speaker driver in the speaker cabinet.


IRS:       Infinity Reference Standard. A large, 7 foot tall speaker system comprised of 4 separate boxes (two for the midrange and high frequencies and two for the bass frequencies). Handmade by the Infinity Company. This speaker is no longer made.




ISDN:     An abbreviation for Integrated Services Digital Network - Basically a way to move more data over existing regular phone lines. ISDN is a digital communications technology that lets both voice and data be transmitted over telephone lines (including both land lines and satellites). ISDN services are available throughout the USA and in several other countries. In most areas it is priced very comparably to the standard telephone service. ISDN is used for phone conversations as well as the transfer of computer information. It can also be used to transmit audio and video, not of professional recording quality, to another computer. (Compare SDN.)

For a more technical description, read on…ISDN usually provides speeds of 56,000 or 64,000 bits-per-second (56 to 64 Kbps). It is potentially capable of 128 Kbps, but the phone company generally limits users to 64 Kbps in most cases. The goal of ISDN is to replace the current telephone network with facilities totally devoted to processing and transmitting information in the digital domain. (See INTERNET2 for recent developments on digital data transmission.)


ISO:       An abbreviation for International Standards Organisation. It is composed of many international specialised committees that have as their purpose to establish technical standards for virtually all technical subjects and trades. Not only do they deal with every aspect of audiovisual specifications, but they cover many other subjects and fields as well. For example, if you owned a machine shop that built small metal parts for special technical machinery, there would probably be ISO standards for such which you would want your product to meet. Companies that build electronic devices also have ISO standards their products should achieve. Virtually any standard that requires broad agreement amongst manufacturers, designers, technicians, etc. has ISO standards. They are heavily involved as well in the audiovisual fields. Established committees of respected audio and video technical engineers and scientists are members of committees that constantly review and establish standards for AV production. The ISO is the accepted source for such standards as all in the industry can then agree and produce products which are broadly interchangeable and usable. The ISO even sets standards for the film industry, such as the ratings for camera film, and for the computer industry, such as the types of connections used to hook up a computer.


ISO CAMERA:      Stands for “Isolated Camera” At a live event, a video camera that has its own built-in recorder connected as a package with the camera itself. It is independent of (“isolated” from) the system of video cameras and video recorders set up between the live event hall and the production truck. Because the iso camera has its own recorder attached and does not depend on the recorders in the production truck, the cameraman can start and stop his camera recording at will. Iso cameras are different than the main cameras used for the event in that the main cameras’ signals are all sent to video recorders inside the production truck. (The main cameras do not have self-contained recorders.) The footage the iso cameraman shoots can be inserted into the video edit as needed. Because the action that an iso camera covers is only intended for occasional use in the edit, it does not warrant recording every minute of an event from that camera’s view. Often the signal of the iso camera is fed into the production truck so that it can be used in the live edit. However, its signal is only recorded by the self-contained recorder in the camera. It is not also recorded in the production truck except for its shots that are used by the Truck Director for the live edit. An example of the use of an iso camera at a live event is a hand-held shot where the cameraman is walking across the stage to get close-ups of a group of award winners.


ISO CENTRE FREQUENCIES:   The audio frequencies specified by the International Standards Organisation (ISO) for use in sound testing and calibration procedures. Note:      This is a term used in the owner’s manual for the Ivie Spectrum Analyser, a device used to measure the different frequencies making up a sound. The Ivie unit itself has these various “ISO Centre Frequencies” written on its display.


ISO-CHRONOUS:        Equal or uniform in time and-or done in equal intervals of time. Also, characterised by motions or vibrations having equal duration. “Iso-chronous” comes from the Greek words meaning, “equal in age or time”. (Iso = equal, and chronus = time.)




ISOLATION: 1) Said in reference to making a studio recording where more than one instrument plays at the same time but the engineer does not want the sound from one instrument bleeding into the other’s microphone. To “isolate” the two instruments, small walls of sound absorptive material are used to create little “rooms” around the instruments, though the players can see each other.

2) Said of any sound treatment that blocks sound or of the capability of a room to block sound from entering or leaving. “That room has good isolation.”

3) The separation between an audio device and everything surrounding it; usually in reference to phonograph tone arms and their platters.


ISP:        Internet Service Provider. There are companies that specialise in and sell access to the Internet. They provide Internet users with the ability to log onto the Internet. They are called Internet Service Providers. The largest such company is America On-Line (AOL). Another large ISP is Earthlink.


ISRC:     Abbreviation for “International Standard Recording Code.” An ISRC is a tracking number encoded into every manufactured compact disc specifically to help enforce the payment of royalties. The ISRC is not embedded into the music programme of the CD, but exists just before the beginning of each song. It is essentially a tracking number and from it one can find the disc’s country of origin, the artist, who owns the rights to the CD’s content, the year of its recording and the serial number of its recording. The ISRC code is used by companies such as BMI and SESAC, to track each time an artist’s song is played over radio or other public broadcast. (See BMI, SESAC.) Any time a radio station plays a song from an artist, a small electronic device at the radio station reads the ISRC code. (The code can’t be heard by a person, but it exists just before each song on a CD and can be read by a computerised tallying device.) Radio stations are required by law to make such a tally and put it onto a computer database. The database then forms an exact listing of every song broadcast by the station, and how many times. This data is then used by record companies and the radio station’s own management and accounts personnel for the payment of royalties. The ISRC is not a type of copy protection, as it does not prevent copying the CD’s contents. It only helps keep track of who is playing the song and how many times for royalty purposes when the playing of the song is done by radio stations, etc. Though not a copy protection code per se, the ISRC code is a digital code that can be put on any digital disc to help with the enforcement of royalty payments. ISRC codes are installed onto a CD during the mastering stage, before mass duplication at a CD replication plant. As of 2001, the Recording Industry Association of America is having a more advanced code developed, for tracking Internet music Internationally.

Note: Dolby has also developed Advanced Audio Coding for similar purposes.


ITU:       Abbreviation for International Telecommunications Union. This is the organisation that sets various standards used throughout the audiovisual industry. They even set standards for loudspeaker placement in surround sound audio systems used for professional mixing purposes. The predecessor of the ITU - the CCITT (Comite Consultatif International Telegraphique et Telephonique), was founded in 1865 and became an agency of the United Nations in 1947. Its purpose was to recommend and standardise telephone and data communication systems for public and private telecommunications organisations. CCITT was renamed as the International Telecommunications Union in March, 1993 and thus became the ITU. They may be contacted at ITU services department, Place de Nations, 1211 Geneva 20, Switzerland. Telephone +41 (22) 730 5554 Fax +41 (22) 730 5337.


ITU-R:   Abbreviation for International Telecommunications Union - Radio. This is the branch of the ITU which was formerly known as CCIR. (See ITU.)


iTV: iTV is an abbreviation for interactive Television. It is the general term to describe TV broadcasts which have interactive capabilities.