Audio-Visual Glossary



TABLE 3:       A chart giving many specifications for DTV (Digital TV) as written and published by the ATSC (Advanced Television Systems Committee.)


TABLE OF CONTENTS:      Abbreviated TOC. Additional data included on a CD, listing the start time of every track on the disc.


TACH:    Short for tachometer, a device which puts out electrical pulses in time to the motion of a rotating disc.


TACH PULSES:     Shortened form of “tachometer pulses.” A “tach” is a device which puts out an electrical pulse each time something rotates. (There are often “tachometers” in cars that show how many revolutions per minute the car’s engine is making.) “Tachs” are often used on film projectors to precisely synchronise sound and pictures. A tachometer, which registers each rotation made by the projector’s motor, is installed in the projector. The tach then sends out electrical signal pulses that are in perfect time with that rotation. These pulses are received by a synchronisation device which is connected to the audio machine. That device then regulates the audio machine to run at the same speed, in perfect synchronisation, with the projector - thus the pictures and sound are “in synch.”


TAD:       Abbreviation for Technical Audio Devices, which is the name of a company that manufactures high-quality loudspeakers. They are owned by Pioneer. There are TAD speakers in each of the Lecture Mix rooms in the Audio Building.


TAIL:      The reverberant decay of the end part of a sound in an acoustical space.


TAILS OUT:  A way of winding tape or film so that the end of the last recorded section is at the outside of the reel. This is how an audio tape is wound when one is done using it. The reason why is that when a tape is wound “tails out” it reduces the print-through at the very head (beginning) of the tape. This is because of the way the tape is layered on top of itself when a tape is wound tails out. When the head of the tape is on the inside of the reel, the section before the start of the sound is layered most closely against either the inner hub of the tape reel or another layer of blank tape. This reduces the amount of print-through on the blank section of tape just prior to the start of the audio program. 


TAKE:     Each time a cine, video or audio recording is made of a specific performance, it is called a “take” (“take 1,” “take 2”, “take 3”, etc.).


TAKE UP REEL:    On a tape recorder or film projector, the reel on which tape or film is wound after it passes through the machine.


TALKBACK:   An audio intercom system that allows the engineer at the mixing console to talk to the performers in the studio or on the stage.


TALKING HEAD:  A film or video shot of a person, showing mainly his or her head and shoulders. The person may be seated or standing, simply talking at the camera. Newscasters for example, are often shot as “talking heads.”


TANNOY:      A brand of loudspeakers made for studio and home applications. They are made in England and unique in that most of these loudspeakers have the tweeter actually inside the woofer with the cone of the woofer acting as a sort of “horn” for the tweeter. This is called a concentric driver.




TAP:       1) In its electrical sense, a “tap” is a connection point. Audio and electrical transformers have “taps.” They are the connection points which send out the power. Different taps on the transformer output different voltages of electricity. 2) To “tap into” an audiovisual device is to connect up to it so one can receive the signal it is producing. “Tap into the first video deck.”


TAPE:     A recording medium, consisting of magnetic particles suspended in a binder and coated on a plastic or film base. Tape is used to record the audio or video information and preserve it for future use. Magnetic tape is used for many different types of recording, both analogue and digital.


TAPE COMPRESSION:       Magnetic recording tape has a certain range of sound volumes that it can accurately record. Every manufacturer of professional audio recording tape issues specifications stating exactly what this range is. When the volume of a sound is too loud going onto tape, it may distort. At the point where the tape has accepted as much volume as it can and still more volume than that is attempting to be recorded, the sound can be heard to compress - meaning it is sort of squashed and is no longer well defined. It may also sound a bit dull and dead. This is called “tape compression,” because the actual recording medium has reached its maximum at handling the sound volume and it is unable to record any louder volume. The result is that the sound coming off of the tape will be heard as somewhat squashed (“compressed”) as compared to what is being sent to the tape recorder.


TAPE DECK, TAPE MACHINE, TAPE RECORDER:       A machine used for recording and playing sound from magnetic tape. Tape decks range from cassette decks and open-reel analogue tape recorders to DAT machines; and from a home consumer VCR to a professional digital videotape recorder. A tape deck is literally any audio or video machine that records and plays back on the medium of tape. Tape decks contain the mechanical parts needed to move magnetic tape across the heads needed for recording and reproducing sound. Some tape decks are simply mechanical transports and heads, with the electronics needed housed in a separate box.


TAPE HISS, TAPE NOISE: The very low volume noise heard when analogue audio tapes are played back. Even blank tape makes a slight “hissing” noise during playback. Dolby Noise Reduction is used to handle this.


TAPE IN:       Short for “tape input.” The connection point of an audio preamp or mixboard that accepts the incoming playback signal of a tape recorder.


TAPE MONITOR: It’s the section of a preamp or mixboard that enables checking (“monitoring”) what has been or what is being recorded on tape. The tape monitor section usually includes its own volume control.


TAPE OPERATOR:      1) The engineer at a live event who operates the video machines that record the event as well as the ones used to play all the event’s videos to the audience. 2) Any technical staff member who operates a tape recorder is sometimes called the “tape operator” or the “machine operator.”


TAPE OUT:    The connectors and electronics in an audio mixboard or home audio equipment that send sound to a tape recorder.


TAPE RECORDER:      A recording machine for audio. “Tape recorder” generally means any such machine, digital or analogue, which records to magnetic tape.


TAPE SELECTOR, EX (I), SX (II), ZX (IV): The tape selector buttons are used for the different types of cassette tape that exist. On some models, the tape selector buttons are for recording only. (Note:   Though the Standard Tech Cassette Deck is intentionally made unable to record to prevent possible erasure of LRH lecture cassettes, some Nakamichi models do use these buttons for playback as well as record. For listening to LRH lectures, the ZX “Type IV” button should be pushed when listening to LRH lectures on Nakamichi models DR 1, DR 3, DR 8, and DR 10.) There are 3 basic cassette tape types. Each uses a different type of metallic particle for recording. “Normal” tape is ferric (iron oxide), chrome is made from chromium dioxide (a mixture of chromium and oxygen), and the very best is “metal” - which is simply iron (no oxide). When the correct button is pushed, the cassette player’s electronics apply the correct electronic processing required for that type of cassette tape. The 3 tape selector positions are “EX (I)”, “SX (II)” and “ZX (IV).” These terms, per Nakamichi, are just made up letters and numbers to market their tape brands. On some of the later model Nakamichi cassette decks, they dropped using these letters and just call the buttons “Type 1,” “Type II” and “Type “IV”. Other brands of cassette tape also adopted this naming system and on earlier cassette decks you will still see such. EX is tape type one (I), the normal ferric tape. SX is tape type two (II), chrome tape, and ZX is tape type four (IV) which is metal tape, the highest grade. There is no tape type three. The cassette tape manufacturers just skipped the number. (See NAKAMICHI CASSETTE DECK FRONT PANEL CONTROLS WHAT THEY ARE AND DO.)


TAPE TRANSPORT:    The various rollers and mechanical moving parts on any audio or video recording or playback machine that uses magnetic tape. The tape is moved across the recording and playback heads by these various mechanisms which, together with a chassis, are referred to as “the tape transport.”


TAPPING:     If you ever wondered how some rock guitarists can play so fast, like Eddie Van Halen (who developed the style), it is because they use a technique where they literally tap the fret board of the guitar rather than doing the usual picking of a string with a pick. They use both hands to tap so it is double the amount of fingers activating sounds from the strings. It is very showy to see live.


TASCAM CASSETTE DECK:       Brand name of a cassette recorder, playback. One Tascam model is used for the slideshow system. It is an unusual deck because it can play back THREE channels off a cassette tape simultaneously. Two of the channels are for stereo audio - the soundtrack which accompanies the slide show. The third channel contains a clock signal that cues the projectors when to change slides. (This signal is not played back through the loudspeaker system, it is sent only to the projector.) This way the pictures stay in synch with the soundtrack.


TAUT:     The word “taut,” in bass sound reproduction, means a loudspeaker has excellent control (starts and stops instantly to make the bass sound). It’s as though the speaker is “tight” - like it moves in a fast tight range of motion to create its sound efficiently. It is not sluggish. The bass sounds snappy and has good punch. A taut bass sound has little, if any, sustain after the note has been played.




TB WOODS:  Brand name of an electronic device used to supply the exact and correct voltage of electricity to film projectors.


TC ELECTRONICS:     A Danish company that makes high quality electronic equipment for musicians and audio studios.


T COMMERCE:     A term regarding interactive Digital TV which allows the viewer to shop for goods and services. The “t” stands for “television.” “Commerce” is an interactive cable TV service, which allows viewers to shop and watch their favourite programs simultaneously.


TDM:      An abbreviation for Time Division Multiplexing. “Multiplexing” is a method of transmitting more than one signal at a time over the same path (e.g. a wire or over the air as in a broadcast). A very common example of multiplexing is a stereo radio broadcast, as it actually has two separate audio signals - a left and a right (channel) - that are being sent over the same radio carrier wave. Multiplexing can also be applied to sending digital information over a wire. In “Time Division Multiplexing,” two or more digital signals are divided into separate groups and transmitted in segments, one group at a time (on the same wire). The separate groups are transmitted so fast that one doesn’t hear or see broken segments of the program. Two or more separate digital television broadcasts can even be done using the same satellite channel at the same time using a form of TDM. Some computer plug-in sound cards (as used in Digital Audio Workstations) also use TDM as a method to transfer digital audio signals into and out from the computer. ProTools uses such a system. When you see a “TDM” designation on a sound card, that is what it means. Equipment manuals will state whether or not a particular digital audio workstation or non-linear editing computer will accept TDM plug-ins. If not clearly stated in the manual, the manufacturer should be consulted before purchasing and installing the plug-in.


TCP/IP: This is an acronym for Transmission Control Protocol - Internet Protocol. TCP/IP is a set of protocols that allow computers with different operating systems to communicate with one another across the Internet.


TDIF, TDIF CARD:      Abbreviation for Tascam Digital Interface Format. 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. It is used mainly with Tascam’s 8 channel digital audio recorders, such as the DA-88 and DA-98 models. (WORD CLOCK is defined separately.)


TDK:       Abbreviation for Tokyo Denshi Kogyo (Tokyo Electronics Corporation). TDK is one of the largest manufacturers of electronic parts and recording media in the world. They make the metal cassette tape used for LRH lectures (not the foreign versions - chrome tape is used for these).


TECH FILMS:        The following is a list of the LRH technical training films. (PUBLIC FILMS are listed separately.)



TR Instruction Films:


      TR-1:     TR's IN LIFE (a public film too)








      TR-5:     WHY TR’s?




      TR-7:     UPPER INDOC. TR’s


      TR-8:     START, CHANGE, STOP


      TR-9:     THE AUDITOR’S CODE


      TR-10:    ASSISTS


      TR-11:    TONE 40 ASSESSMENT


      TR-12:    THE SOLO AUDITOR


      TR-13:    THE SESSION


      TR-14:    CONFESSIONAL TR’s



                    THEIR CRITICISM




E-Meter Instruction Films:


EM-1:     MAN THE UNFATHOMABLE (a public film too)


      EM-2:     THE TONE SCALE










      EM-6:     FALSE TONE ARM


      EM-7:     BODY MOTION READS     




      EM-9:     E-METER READS




      EM-10:   PC INDICATORS







TECH BALCONY: Slang term for the balcony in the FH auditorium and in the Great Hall at Saint Hill from where the house audio, lighting and film projection are controlled. This term also applies to any venue’s balcony that holds the technical control centre for house audio, lighting and film projection.


TEF ANALYSER:   A brand of computerised audio analyser.


TELCO:  An abbreviation for telephone company. “Telco” applies to any telephone company - General Tel, Pac Bell, etc. Telephone companies provide Internet connections via land lines and satellite as well as other services in addition to phone services.


TELECASTER:       One of the most famous electric guitars ever made. Initially named the “Broadcaster” in the early 50’s, the Fender company had to change the name (for legal reasons) and did so to Telecaster. It was an instant hit. It is the guitar sound heard on countless country and western songs and on many rock tunes too.


TELECINE:    The process whereby motion picture film footage is copied onto videotape.


TELECINE LINE: The production line in the Gold Film Lab where a copy of each Rushes Print is transferred onto video for use on the AVID editing line. Sound is also transferred from a DAT tape. Both sound and pictures are transferred in synch onto a Betacam videotape that can then have its sound and pictures loaded into the AVID.


TELECOMMUNICATIONS: The science and activity of information transfer using wire, radio, optical, or electromagnetic channels to transmit and-or receive signals for voice or data communications using electronic means.


TELECONFERENCING:      Two-way electronic communication between two or more groups in separate locations via audio, video, and-or computer systems.


TELEFUNKEN:      The name of a German company that manufactured very high quality microphones. This company was the predecessor of Neumann Microphones. Telefunken produced excellent vacuum tube microphones that are very much sought after by audio engineers. There is a Telefunken tube mic in the vast collection of microphones in the LRH Music Studio.


TELEPHONE JACK:     The full and more formal name for “phone jack” which is a jack that receives a plug with a diameter of 6.5mm and a length of 30mm; used for interconnecting audio. It got its name from the early days of telephone, when operators would route calls by plugging in a cord to connect one caller with another. Telephone jacks and plugs are strong and hold up to continuous use. They come in stereo and mono versions.


TELEGENIC: The quality of being presented well over television. 

TELEPROMPTER: A video device used to display the dialogue that a performer is to speak by scrolling the lines during the performance. The teleprompter is under the control of an operator, who controls the scrolling to keep up with the performer’s pace. Clear panes of glass reflect the words so only the speaker can see and read them. Also used by newscasters when they look directly into the camera all the time and seem to have their lines memorised, they are actually reading the words off a clear pane of glass through which the camera is shooting.   


TEMPO: The number of beats per minute in a musical performance.


TEMPORAL ALIASING:      “Temporal” means “relating to time,” and “alias” comes from the Latin word meaning “otherwise.” Temporal aliasing is a video picture defect that occurs when an image moves too fast for the video equipment to track with. An example of this is wagon wheels that appear to rotate backwards. The rate of the video frames moves a bit too slow to accurately show the motion of the spokes.


TENOR: The word “tenor” comes from Latin meaning “to hold a tone.” An adult male singing voice higher than a “baritone” and lower than an “alto.” (An alto is the lowest female voice and the highest male voice in singing.)


TENOR GUITAR: A small acoustic guitar with only 4 strings. It plays with a higher pitch than a standard size guitar. Also, a standard size acoustic guitar can be strung with extremely light gauge strings and tuned an octave higher than normal, so it will play in the range of a tenor guitar.


TENOR SAX: There are four different types of saxophones - baritone, tenor, alto and soprano models. They each cover different ranges of notes - the baritone being the largest of the four and it plays the lowest notes of the four.





10.2 SURROUND:       A huge surround mix - with 10 channels plus subwoofers done by some film studios for special release showings and to accommodate any future needs in the years to come. It is not a Dolby or DTS processed mix but a 10 channel discrete mix, with 2 subwoofer channels.


10,000 Hz TEST TONE:     It is vital in producing an audio program 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 and engineers use “test tones” to do these tests and adjustments. When the adjustments are done, the equipment is said to be calibrated. A “10,000 Hz test tone” is a principal test tone commonly used to calibrate the treble region of equipment (tape recorders, etc.)


TERABYTE:   A trillion bytes of computer storage or information. The exact amount of bytes contained in a terabyte is 1024 gigabytes. “Tera” is from Greek, meaning “monster.”


TERRESTRIAL, TERRESTRIAL BROADCAST:       Any over the air broadcasting using earth based (non-satellite) transmitters and antennas. For example, a TV signal sent by a local station and received over a rooftop antenna by a home consumer is terrestrial broadcasting.




TERMINATION, TERMINATE:  As applied to video, a 75 ohm resistor connected to the end of a line carrying a video signal, which keeps the signal from bouncing back up the line and distorting the picture.


TEST DISC:   1) A test run done of a CD or DVD for quality checking before the full run of many thousands is authorised. 2) Any CD or DVD used for testing or run as a test.


TEST PRESSING: 1) One of a few initial phonograph record copies, pressed from the first stamper made, which is listened to and visually inspected to approve the quality before production copies are made in volume. 2) A test disc.


TEST TAPE:  1) A magnetic audio tape with tones of various frequencies, all precisely recorded at an exact specified volume, used for tape machine calibration. 2) One of a few initial tapes made with high-speed duplication and listened to before approving production copies to be made in volume.


TETRODE:     A four electrode vacuum tube used in some audio amplifiers. (See full description of all types of tube amplifiers at PENTODE.)  


TEXAS INSTRUMENTS:     Abbreviated TI. An electronics firm that makes electronic parts commonly found in video projectors. They also make many other consumer electronics such as calculators, etc. One will frequently hear or read about “TI DLP” or “TI chips” - these are the “Digital Lens Projector” chips used in DLP projectors.


      TEXTURE:     1) Audio electronics and loudspeakers can impart their own “texture” to reproduced sound. It is a very slight type of distortion. 2) It can be a slight “roughness” to the sound or even the opposite - a “smoothness.” The word “texture” is used to describe such. For example:     Every musical instrument and every singer has a certain texture or textures to their sound or voice. It is one aspect of the many qualities that make an individual sound unique and different. A voice can have a rough texture. Any sound can have a “texture.” A Mixer can give textures to the sounds he is mixing or take textures away if they are unwanted. Audio loudspeakers and audio electronics can impart their own textures to the sound due to the characteristics of their design and parts used.


THD:       Total Harmonic Distortion. See HARMONIC DISTORTION.


THEATRICAL:      A type of movie. It is a full length Hollywood type movie - with a story, as played in commercial theatres, as distinguished from documentary and educational films. 


THICK:   In sound, describes heavy bass notes. Dense, thick and big. A thick mix can have too much lower midrange and upper bass frequency content so one cannot hear all the individual sounds clearly.


THIN:     In sound - very deficient in bass frequencies. Lacking frequencies below 500 Hz. The low midrange, upper bass is missing from a sound’s expected character. “That cello sounds thin.” Sounds can be incorrectly thin in a mix, or a loudspeaker system can make music sound thin if the full range of lower frequencies is not accurately reproduced. Any instrument or voice, even a female singer, can sound thin if the lower frequencies of that sound are removed or not captured in the recording to begin with.


35mm RELEASE PRINT:   A motion picture film print that is the final releasable version of a film. A small number of 35mm Release Prints are printed for use at Gold, Flag, the Ship and other areas set up for 35mm film projection, plus copies on the shelf per Film Lab production line documentation.


THREE DIMENSIONAL:     When music has excellent spatial qualities and sounds very big, it is said to sound “three-dimensional.”


3-D PERSPECTIVE:    See THREE DIMENSIONAL. It’s the same thing.


3M PROJECTOR: A brand and model of digital video projectors. 3M = Minnesota Mining and Manufacturing.


THREE TO ONE RULE:       A rule regarding the placement of 2 or more microphones, each intended to pick up its own sound source, to prevent one source interfering with another. The rule states that the distance between microphones must be at least three times the distance that each microphone is to its sound source.


3:2 PULLDOWN:  The term “3:2 pulldown” pertains to the action of taking a film shot at 24 frames per second (fps) and transferring it onto video which runs at 30 frames per second. The term “pulldown” comes from the type of film projector mechanism used in this process. This mechanism moves the film through a projector, lamp and camera rig that records each frame. The mechanism pulls the film down into the exact area of the projector (the “gate”) where the individual film frames pass directly in front of the lamp and camera. When transferring a 24 fps film onto 30 fps video, a special handling is needed. Somehow there has to be some extra frames of the film made so as to create 30 fps video. 3:2 pulldown is the specific process that does this. Here is how it works:  The professional copying of a film to video is done by a “telecine” machine. It is a combination of a projector and a video camera. As the film passes in front of a lamp, a high quality video camera takes a picture of each frame of film. With the telecine’s video camera and recording process, a frame of video is actually broken up into two parts. Each is called a “field.” Two fields equal one frame of video. The camera actually shoots individual fields of video. 3:2 pulldown is a process where the camera looks at the first frame of film and takes 3 video fields worth of video picture of that one frame of film. Then the telecine machine presents the next frame of film for the video camera, and the camera takes 2 fields of video. You can see that when the first frame of film was shot by the camera, 3 fields were taken. That’s one more field than what is needed to create a frame. So, an extra field now exists. The camera makes an extra video field picture of the film of every other film frame, of which there are 24 per second. At the end of a second’s worth of time, there now exist enough extra fields of video to make up the difference between 30 fps video and 24 fps film. The 3:2 pulldown mechanism of the telecine machine actually allows every other frame of the film to pause very briefly to allow the video camera to shoot that extra field. It “pulls it down” in front of the camera slightly longer. Bright light passes through the film and the camera takes a video shot of the frame - either two fields or three fields worth. This results in a 30 frames per second video recording of the original film footage. As all conventional video equipment operates at 30 frames per second, the telecine copy can now be shown on a video system.




      THREE-WAY:       A type of loudspeaker composed of three different ranges of speakers - a woofer, a midrange, and a tweeter. Individual speakers like this are called “drivers.” These are usually all mounted within one cabinet. Other times, they may be in individual cabinets but wired together so as to operate as one speaker “system.” Sometimes there are more than one of these individual drivers, but the system is still “3 way” as the audio signal is split up by the crossover into bass, midrange and treble feeds which are routed to the appropriate speaker drivers that handle those frequencies.


      THRESHOLD:       The level at which an audio electronics device will begin to change the volume of a sound sent to it. For instance, a limiter does nothing to the signal until the volume of the signal exceeds a certain threshold. Above this level, the limiter reduces the gain so that the output volume (level) does not increase despite the incoming volume increasing above the threshold.


THRESHOLD OF FEELING (sound being too loud):   The sound pressure level at which people feel discomfort (not pain) 50 percent of the time. Approximately 118 dB SPL at 1 kHz. (Compare THRESHOLD OF HEARING and THRESHOLD OF PAIN.)


THRESHOLD OF HEARING:      The lowest level (volume) sound that an average listener with good hearing can detect. On an SPL (sound pressure level) meter, 0 dB SPL designates the threshold of hearing. (Compare THRESHOLD OF FEELING and THRESHOLD OF PAIN.)


THRESHOLD OF PAIN:      The sound pressure level at which people feel actual pain 50 per cent of the time. Approximately 140 dB SPL at 1 kHz. (Compare THRESHOLD OF HEARING and THRESHOLD OF FEELING.)


THROAT:       The small opening in a loudspeaker assembly through which the sound passes from the driver (the inner part of the speaker where the electronic vibrations are converted to mechanical motion) to the outer part of the speaker (where the mechanical motion is changed to air vibrations). Also called mouth.


      THROW:        1) Distance from film projector lens to screen surface. 2) In loudspeakers and microphones, the amount of movement that the diaphragm can make (without restriction) to produce or pick up the sound. 3) The distance a loudspeaker’s projected sound can travel with acceptable fidelity for a listener. Throw specifications are especially critical when setting up live PA sound systems, where some audience is seated quite far back and some very near the stage. A properly designed and installed loudspeaker system for live events will reach all of the audience with good clarity and impact of sound. 4) In loudspeaker design, the distance a speaker travels forward and back within its cabinet as it reproduces sound. “Short throw” speakers are designed to cover short distances, while “long throw” versions can project their sound quite far - hundreds of feet.


THUD (THUDDY):       A poorly recorded or mixed bass or drum sound that sounds dead and lacks impact. A poor loudspeaker system can make these sounds thuddy as well. Any sound that sounds like a “thud.” The notes are not distinct yet they may overpower other sounds in the mix.


THUMPY:      Usually refers to any musical instrument with too many low frequencies and played in a way that the sounds sort of “thump” undesirably without good clarity of each individual note played. The notes are not distinct yet they may overpower other sounds in the mix. They do not sound good or fitting for the piece of music. Another example of thumpy is when an acoustic guitar is mic’d too close to the sound hole or when recording a piano, a noisy piano pedal mechanism. Any sound that sounds “thumpy.”


THUMPER:    A “thumper” or “thumper beat” is a very low-frequency bass sound used to give live dancers the beat of a song while recording live music so they stay in time and synch with each other and the music. The thumper sound is filtered out (removed) from the mix so one only hears the music.

For technical specifications, read on… The thumper is usually a tone (around 30 Hz) triggered by a noise gate keyed to a click track.


THUNDEROUS:    Deep bass sounds which have impact like thunder. Extended, powerful, big low-frequency response below about 50 Hz.


THX:       An abbreviation for, Tomlinson Holman Experiment.” THX is surround sound specifications for audio components (i.e. amplifiers, processors, speakers, etc), for both home and theatre. Established by LucasFilm, THX specifications are designed to provide consistent audio quality in theatres, up to the standards that the film was mixed to sound like. Professional and home audio equipment can carry the THX logo after obtaining THX certification from LucasFilm. THX originally came about after the first “Star Wars” film was released in 1977, mainly due to the fact that theatres were playing films too quietly. So, THX had very stiff specifications for audio volume. George Lucas, the creator of “Star Wars” had a man on his staff named Tomlinson Holman. The name “THX” comes from his name, plus the word “Experiment” - The Tomlinson Holman Experiment. It was Holman, a skilled audio technician and engineer, who established the specifications for theatres. If theatres met these, they could display the “THX APPROVED” logo. THX is not a brand name, it is a company that issues requirements, inspects that they are met, and issues licenses that they are. The “Ultra” specification is the THX certification for home consumer equipment that meets its requirements. Not all equipment manufacturers seek such a rating, mostly due to expense. But when the equipment does have the rating, it is also equipped to perform proprietary, THX surround sound functions not available on non-THX systems. In adapting their standards for home equipment, THX took into consideration how loud consumers listen to movies at home - usually quite a bit softer than full theatre volume. THX also specifies that for home rooms, because the influence of sounds reflecting off walls was less than in a large theatre, less expensive loudspeakers can bear the THX logo. THX has specifications which must be met for theatre construction. For example, you mustn’t be able to hear the sound from an adjacent theatre through a wall. THX inspects theatres, grades them, assists with recommendations for improvements, helps in designing theatres, etc. - if you want to display their logo. THX, basically then, is a set of standards and recommended practices established by George Lucas and Tom Holman to ensure that moviegoers would see and hear what the filmmakers intended. In summary, there are different standards for movie theatres and consumer home theatres. THX is not a brand name, it’s a seal of approval. For home surround sound electronics, if the electronic equipment is to bear a THX seal of approval, some additional electronic features, designed by THX, must be included. Note:     THX licenses and certifies Dolby surround home electronics, not DTS, because DTS will not incorporate certain THX features in their system. (These features are described in full under the glossary entries THX RE-EQUALISATION, THX TIMBRE MATCHING, THX DECORRELATION.)


THX DECORRELATION:     The term “decorrelation” is an older THX requirement for HOME theatre surround sound in THX versions of Dolby Pro-Logic surround sound. Any THX certified home electronics with Dolby Pro-Logic have “decorrelation.” Note that Dolby’s newer versions of home surround sound (Dolby Digital - all versions) do not need or have this feature. It is only for the older Dolby Pro Logic soundtracks that decorrelation is used. The prefix “de-” means to reverse the action of, and “correlation” means mutual relationship or connection. THX Decorrelation specifically has to do with causing the rear surround loudspeakers (left and right) which, in Dolby Pro-Logic, is a one channel (mono) audio signal sent to both the left and right surround loudspeakers out in the room, to shift slightly on a constant basis their phase relationship to each other. This is done so slightly that the home consumer never notes the shift, but the effect created is that the sound produced by the surround channels is made bigger sounding. The reason for the feature was that the rooms in homes are small compared to a large professional theatre. So THX required this decorrelation of the two rear surround loudspeakers to help make the film sound bigger, more like it would in a large movie theatre. It was not required in THX approved general cinema theatres that use (or used) the first Dolby Stereo surround, the home version of which is Dolby Pro-Logic. THX Decorrelation was technically called “phase dithering.” THX Decorrelation is not used on any of the newer Dolby Digital Surround Sound formats, only the original Dolby Pro-Logic, and only if that was “THX Certified.” NOTE:    THX only certifies Dolby’s surround sound for home use, not DTS.


THX EX: See THX Surround EX. It’s the same thing.


THX PHASE DITHERING:  Another technical name for THX Decorrelation used on THX certified versions of Dolby’s original Dolby Pro-Logic surround sound for home consumers.


THX RE-EQUALISATION:  This is a feature on THX certified home consumer digital surround sound equipment using Dolby Digital Surround Sound processing. The feature is actually a process applied to a film’s soundtrack as it is played over home surround speakers. It is called “re-equalisation” because THX has designed the system to compensate for boosted high frequencies - extra treble EQ added when the film’s soundtrack is mixed by the studio. The studios add high frequencies to help the sound reach the audience in large theatres who are sitting a distance from the screen compared to home viewers using their private surround sound systems. Also, professional theatres usually have more sound absorption materials in the room than home theatres. Therefore the high frequencies are boosted to help the film sound’s presence in the larger theatres. At home, however, the sound can be too bright - the high frequencies are too loud. The THX “re-equalisation” lowers this high frequency content so, as THX says, “you can hear the same thing in your home as you do in the cinema.” It does this in the front speakers. This is included in any THX certified home surround sound electronic equipment. It is not required in THX approved general cinema theatres. THX only certifies Dolby’s surround sound for home use, not DTS.


THX SELECT:        See THX ULTRA for details.


THX SURROUND EX:  This is the Dolby Digital Surround system as certified by THX. (THX does not certify DTS as DTS does not include certain THX electronic requirements in their surround system.) “THX Surround EX” is the THX certified version of the Dolby EX system for both professional theatres and home consumer use. The THX certified system is the 7.1 (7 channels of audio plus one subwoofer channel) version of Dolby EX for both general cinema theatres and home use. The 7.1 version of Dolby Digital Surround Sound adds two channels of “Back Surround” to the rear wall behind the viewers in both cinemas and home applications. However, in professional theatres, certain THX electronic features required in the home version are not required. (Note:      In professional cinema theatres, THX certification really has to do with the theatre’s construction, selection of amplifiers, selection of loudspeakers, etc. whereas the home versions must have certain electronic features that help the sound appear to be playing in a larger, like-like room, not just a small room as commonly used in consumer home theatre.) Specifically, in HOME consumer systems THX certification calls for two very specific electronic specifications not normally in Dolby EX. These home features are defined as separate entries in this glossary. (See THX RE-EQUALISATION and THX TIMBRE MATCHING.) THX Surround EX is still “Dolby AC-3” (Dolby Digital) in terms of its basic Dolby processing.


THX TIMBRE MATCHING: This is a feature included in THX certified home surround sound audio equipment. It is added to the Dolby Digital Surround Sound processing whenever the home consumer surround sound system bears the logo of THX certification. THX Timbre Matching is as follows: In a surround sound system, the surround speakers are often at the sides of the listeners or even behind them. “Timbre Matching” is a process whereby the sound quality (“timbre”) of the surround speakers is adjusted until it matches the timbre of the front speakers. It compensates for their different positions within the room. This is done per a system worked out by THX and installed in the Dolby surround sound processor of consumer level surround sound receivers and processors. These electronic features are not required in THX approved general cinema theatres due to the fact that the rooms for such theatres are large and therefore the sound is more evenly presented to the entire audience with numerous loudspeakers around the room. Note:   THX only certifies Dolby’s surround sound for home use, not DTS.


THX ULTRA, THX ULTRA CERTIFIED:   The THX- specifications for home theatre surround sound applications are known as “THX ULTRA” and this is commonly printed on home consumer audio equipment that meets THX specifications and includes several THX-only electronic features designed to help the home surround sound system better simulate what a big commercial theatre sounds like. THX has another rating system, lower than “Ultra,” called “Select,” for less expensive home theatre components. THX did not formerly do much certification of home audio equipment for home theatres. It more concentrated on professional cinema equipment with just a few home electronics manufacturers seeking THX certification, so as to increase sales due to the THX logo being on the home type gear. In reality, the THX specs were pretty stiff for home gear. The specs were really geared around professional cinema requirements. Now, however, THX certifies more home consumer gear and to have that gear include some special features THX requires. The “Ultra” specifications are based on the premise that most home consumers have large listening rooms for their surround sound home theatre systems. Also, in adapting their standards for home level equipment, THX specifications take into consideration the fact that home listeners don’t play films as loud as a large commercial theatre. THX also notes that for home rooms, the effect of sounds reflecting off walls was less of an influence than in a large theatre. So, less expensive, more simply designed loudspeakers can now bear the THX logo. (Prior, THX-approved loudspeakers had to have narrower dispersion so as to limit the amount of sound hitting walls in the theatre.) The new “Ultra” specifications are really a relaxing of THX’s spec's as set for major theatres so that equipment intended for home applications can still bear the THX logo and meet the higher standards that THX insists upon.


TI:  See Texas Instruments.


TIE LINES:   Cables (wires) with connectors at both ends, usually run through walls or floors, so that a signal can be sent or picked up from some remote location. Such lines “tie” areas together (provides them signals from a remote source).


TIGHT:   1) Bass reproduction that is well controlled, free from hangover (no excess sustain or lingering of the note), not slow. 2) Stereo imaging that is specific, stable, but still has a large soundstage.


TIGHT PITCH:     A singer or musician playing an instrument who is right on the exact note. Not out of key.


TILT:      1) To aim a loudspeaker upward or downward. 2) When the frequency response of audio equipment or a mix has a broad general bass boost or drop or broad general treble boost or drop, it is said to have a tilt. “The speaker has a bass tilt up.”




TIME BASE:  The number of pulses, advances per beat in a simple clock signal. (See WORD CLOCK for description of “clock.”)


TIME BASE CORRECTOR (TBC):     A device that corrects, within limits, the time stability of a video signal. This includes correcting the vertical and horizontal jitter sometimes found in the playback of a videotape machine. Many TBC's also include a processing amplifier that allows the operator to adjust the output video and colour levels. Optical effects such as fades, dissolves, wipes and keys must be made through a TBC to eliminate the inherent jitter in the output signal of a VTR. Otherwise, the optical effect will contain so much horizontal and vertical jitter that it will be unusable. 


      TIME CODE: Time code is an electronic signal that contains a precise record of the duration of a recording or playback. Hours, minutes, seconds, frames and fractions of frames (called sub frames) are contained in a time code signal. It is used for synchronising different recorders, such as an audio recorder and a video recorder together so the sound and pictures match up at all times perfectly. Time code was initially invented for the motion picture business, as a method of synchronising the pictures recorded in the frames of a camera to the sound recorded on a tape recorder.


TIME CODE GENERATOR: A signal generator specially designed to generate SMPTE time code at any of the international formats and rates. (SMPTE is an abbreviation for Society of Motion Picture and Television Engineers - organisation that sets standards and specifications for the A.V. industry.)

TIME CODE READER: A counter designed to read and display time code.


TIME CODE SLATE:    A time code slate is a clapper board. However, unlike an ordinary clapper, a digital clock readout on the time code slate also displays precise time code and gives the ability to be 100% accurate in time with the camera and sound recording equipment. In some of these time code slates (called “smart slates”), a time code generator is installed inside the slate itself.


TIME CONSTANT:       See the glossary entry in the “S” section at 70 μs EQ, 120 μs EQ.




TIMER:  A switch on Nakamichi cassette decks. Some consumers wish to record a radio program at a certain time during the day, but they may not be in the house. So, they could use a timer that turns the cassette deck on at the desired time. Nakamichi never sold a timer. However, consumers could purchase one from Radio Shack or wherever, plug the Nakamichi deck into the timer and the timer into the wall outlet, and the Nakamichi would start right up. PLAY or RECORD could be pre-set to happen when the timer started. (See NAKAMICHI CASSETTE DECK - FRONT PANEL CONTROLS WHAT THEY ARE AND DO.)     




TIME SQUEEZING:     A feature on some audio computer equipment, such as DAW’s (Digital Audio Workstations) and some digital mixing gear, which can literally shorten the length of time a given portion of sound requires to play and be heard, but without other audible changes to the sound’s quality. Before digital audio, if a sound was to be speeded up, recording tape was sped up (made to pass faster in front of the record machine’s playback head). Of course, this could only be done a very little bit before the recorded voice would start to sound like a chipmunk. Time Squeezing uses computer digital processing to speed up a portion of audio, but without audible degrade. (Some radio stations use Time Squeezing on a song, commercial or other programming into a given time slot.)


TIMING 1:     See RHYTHM and PACE.




TIME SHIFT TV:  A special type of television receiver that gives viewers the capability to choose what time he or she views a television program. The viewer can “shift the time” of the showing to fit personal schedules. This is done with interactive television by using a menu control to access the station and program one wants to watch, when one wants to watch it. The station airing the program has huge servers that store all their programs and allow their viewers to select the time of their showing.


TIME STAMPS:    Time stamps are digital codes containing exact synchronisation and timing information. These codes are embedded into video and audio signals early in the production stages of an A.V. product. Usually the digital audio or video editing computers automatically time stamp the various shots and voice clips, as they are being edited or mixed. The time stamps are used so the sound and pictures can be precisely identified, located, placed in an edit or mix and kept in synch throughout the post production cycle. An additional use is to verify and correct, if necessary, the synchronisation of the sound and pictures before broadcasting.


TIME WINDOW:  A model of loudspeaker manufactured by the DCM Corporation. (DCM stands for, “Distinct Clear Music.”)


TINNY:  Telephone-like sound. No bass frequencies and the midrange is boosted. The audio sounds as if it’s coming through tin soup can with strings tied to them.


TINY TELEPHONE JACK, PLUG:      A smaller version of the phone jack, plug used in many patch bays. Abbreviated TT.


TIPPED-UP: Having a rising high-frequency response (boosted treble).


TIP RING SLEEVE:     This looks like the common connector on the end of a headphone cord (not the miniature one, the one that is ¼ inch in diameter and 1¼ inches long). Also called a ¼ inch plug. TIP:  The (+) signal carrying part of a phone plug. Ring:      The (-) signal carrying part of a phone plug. Sleeve:  The grounded part of a phone plug. Abbreviated TRS.


TIVO:     This is a brand name of PVR - Abbreviation for Personal Video Recorder. (See PVR for full definition and description.)


TIZZY:   Very hyped-up high frequencies to the point where the sound is unnaturally trebly and uncomfortable to listen to. Sibilance of voices is accentuated. High frequency instruments are shrill.




TOE IN: The angle a loudspeaker is aimed inwards, angled towards the main listener position.


TOGGLE SWITCH:      Any switch with a lever that connects or disconnects one terminal in a circuit with another or others. Toggle switches are used on many different types of audiovisual gear. Any switch that turns something on and-or off can be called a toggle switch, like the power “on-off” button on a DVD player. Even an ordinary light switch is a type of toggle switch. There are also toggle switches made that have more than two positions such as, “on - off - on”, for example a tape selector switch on a preamp that has “Tape 1 - Off - Tape 2”.


TOGGLING:  To switch back and forth between two or more different things.


TONAL QUALITY:       The degree of accuracy with which recorded and reproduced sound duplicates the exact characteristic timbre of the instruments or voices as they were originally heard in the physical universe.


T-1, T-2, T-3, T-4:      Designations for a special type of connections that can send large amounts of data. Used for phones so that many separate phone calls can be sent on one line. Also used for Internet and computer communications connections. It is a high-speed digital data channel that is a carrier of voice and-or data. “T” stands for “Transmitter”, and 1, 2, 3 and 4 indicate connector versions 1, 2, 3 or 4 - ascending numbers indicate higher capacity to transmit more phone calls or other data over a single line (1 being the lowest capacity and 4 being the highest and fastest). For more technical data, read on…T-1, T-2, T-3 and T-4 connections are actually digital to analogue and analogue to digital converters which change voice and-or other information from the analogue domain into digital on the transmitting end and from digital to analogue on the receiving end. These devices compress the signals before sending them on the line and, for example, that’s how so many separate phone calls can be sent on one line. T-1 has 24 voice channels, T-2 has 96, T-3 has 672 and T-4 has 4,032. T-1 is a leased-line connection capable of carrying data at 1,544,000 bits-per-second. At maximum theoretical capacity, a T-1 line could move a megabyte in less than 10 seconds. That is still not fast enough for full-screen, full-motion video, for which you need at least 10,000,000 bits-per-second - so neither T-1 nor T-2 are capable of handling that. However, the T-3 is capable of carrying data at 44,736,000 bits-per-second, which is more than enough to do full-screen, full-motion video. T-4 handles 274,176,000 bits per second (227.176 Mbps). (T-1 is the connector commonly used by the phone company to connect networks to the Internet.)


TONE:    1) A single audio frequency of exact pitch. 2) Short for tonality - the timbre of a sound. 3) The bass, midrange and treble frequencies of an audio program.


 TONE ARM: When playing a phonograph record, the tone arm is that assembly which is brought over to and gently lowered to the record. It houses the diamond cartridge that picks up the sound from the grooves.


TONE CONTROL: A control on audio electronic equipment that allows one to adjust the amount of bass (low frequencies) and treble (high frequencies) heard over loudspeakers or headphones. There can also be an additional control for “midrange” (the middle frequencies).




TOO MUCH HALL:       Too much influence from the room or hall when trying to record, mix and-or listen to a performance - either live or pre-recorded. The sounds are made indistinct to a degree, due to the reverberation, ambient sound and other characteristics of the hall or listening room.


TOO RECESSED:  When a mix, or parts of it, seem too distant from the listener; if they are hard to hear, have no presence, or seem dull (lack treble).


TOO UP FRONT:  The mix, or parts of it, when played over loudspeakers, is uncomfortably or undesirably too forward (too “in your face”). The sound is not integrated with the rest of the mix.


TOP:       The high treble, the range of audio frequencies above about 8kHz.


TOP AND TAIL:   This is a term found in the SADiE manual. A slang term for the starting point (“top”) and the ending point (“tail”) of a sound recorded on tape or other storage medium. Further, it means to remove the excess time before the starting point and after the ending point of a recorded sound.


TOPOLOGY:  Said of the design, layout and construction of an electronic circuit board. “The amplifier’s topology is very advanced.”


TO PULL SOMETHING THROUGH ON A MIX:      To make a sound within a mix more present and noticeable.


TOROIDAL TRANSFORMER:    A transformer whose wires have been wound into a circle. This is a type of transformer designed to handle supplying power to electronic circuits. It is sort of donut shaped. This design is used in the power supplies of many types of audio equipment because it puts out less hum interference than other types of transformers. Due to the way its individual wires are wound and to the overall shape of the toroidal transformer, there is much less an electrical field surrounding the transformer - compared conventional square shaped transformers. As a result, there is less hum interference present to introduce noise into the audio electronics.


TOSLINK INPUT, OUTPUT:      A type of optical output and input for transmitting digital audio. It uses fibre-optic cable and 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. “Toslink” is a generic name for this type of connection.




TRACE:  1) The pattern of light seen on an oscilloscope or other test instrument screen used to measure electronic phenomena. (An oscilloscope is a piece of electronic testing equipment with a small display screen upon which one can see the patterns of signals.) A trace is the narrow line seen on the screen - the picture of a signal. 2) One of the many conductive paths (traces) on a printed circuit board.


TRACK:  1) The path on magnetic tape along which a single channel of sound is recorded. 2) One audio recording made on a portion of the width of a tape. 3) A part of the audio tape that has one channel of audio recorded onto it. For example, on a standard stereo audio cassette there are four tracks, two for each direction so one can listen to both sides A and B with stereo (which requires two channels - one track for each channel). The large multi-track tape recorders used in professional audio studios have up to 24 or more tracks. When speaking of a tape recorder or mixboard, one refers to “channels” - each channel processes (deals with) one track. Track is more correct when speaking of the tape itself or when referring to what is recorded on the tape. “Channel” refers to the section of a mixboard that the tape machine is connected to. “The singer is on track 12.” “Turn up the volume on channel 12.” To “add a track” means to record an additional performance track for a song or piece of music. 4) Any song on a CD or record - the entire song - is called a “track.” A CD can have up to 99 tracks. 5) In computerised audio editing, a “track” is a whole, original audio recording. Examples of tracks include the entire soundtrack for an audiovisual product, and an entire song and an entire LRH lecture. In the SADiE, a Track is identified by a name and will remain on the disc until deliberately deleted. 6) The tight spiral path of pits and lands on a CD or DVD.


TRACK-AT-ONCE CD: This is a term found in the SADiE digital audio computer manual. When recording a CD using the SADiE system, it is possible to record one song or a single portion of an audio program only, and then at a later time, go back and record the next one to that same CD. This method is a way to assemble your audio tracks onto a CD as they are completed, and not wait until all tracks for the CD are completed. For example, if mixing samples for a lecture series were being compiled onto a single CD, each mix could be recorded to the CD on successive days as they are completed. This is referred to as recording a “Track-At-Once CD.” Technical note:   This method (this feature of the SADiE computer) is not recommended for final CD recordings as there may be glitches between tracks. SADiE recommends the “Disc-At-Once CD” feature be used as it creates the entire CD, all tracks, in one sitting.


TRACKING:  1) The angle and speed at which magnetic recording tape passes over the heads in a video recorder or audio recorder. 2) In phonograph record playing, tracking is the ability of the phonograph needle to track the record’s grooves. 3) The control on a VCR that allows one to adjust how accurately the playback head follows the audio and video signals recorded on the videocassette. If you are playing a videotape and the picture is unstable and the audio is distorted, noisy or missing altogether, often the tracking control will fix that. One just gradually turns it back and forth to make the adjustment.


TRACKING ERROR:    In playing a phonograph record, the tone arm should hold the cartridge as perpendicular to the record's surface as possible. Tracking error is expressed as the number of degrees away from perpendicular. 


TRACKING FORCE:    The downward pressure of a phonograph needle into a record’s grooves. Measured in grams.


TRACKING PROPERLY:     Said of a phonograph tone arm that is properly adjusted and riding in the record grooves correctly for best audio quality.


TRACK PITCH:     The digital information on a CD or DVD is recorded in a continuous spiral track (path) of pits and lands. The distance between successive turns in the spiral is called the “track pitch.” (One definition of the word “pitch” is the distance between two things, such as the distance between the individual threads on a screw.) The individual turns of a CD’s continuous spiral track are about 1/30th the width of a human hair, and their pitch is measured in “microns” (millionths of a meter). The “track pitch” of a CD is about 1.5 microns.


TranFIFO:     This is a term found in the SADiE digital audio computer manual. “TranFIFO” is an electronic circuit used in AMS Neve (brand) digital audio workstations (DAWs). TranFIFO is the interface between the workstation’s computer hard drive and the DSP (digital signal processing) section. This type of interface was used in older versions of AMS Neve DAWs and is rarely found today. “Tran” is an abbreviation for Transmission, and “FIFO” is First In First Out. TranFIFO is the method a computer uses to process a data file containing many separate elements. Items to be sent out of the computer are transferred in the same order in which they were originally assembled (“first in, first out”).


TRANSDUCER:     Comes from the Latin words meaning, “to lead across.” A “transducer” is a device that converts one form of energy into another. Examples are a microphone, which converts air vibrations into the electronic vibrations of an audio signal and a loudspeaker, which converts the audio signal into sounds (“air vibrations”) one can hear.


TRANSIENT ATTACK: How quickly audio equipment can respond to sudden changes in dynamics (the volume going low or loud).


TRANSIENT RESPONSE:   The ability of a loudspeaker to respond to any sudden change in the signal without blurring (smearing) the sound. A speaker that can react quickly to rapid changes in sound has "good transient response”.


TRANSISTOR:     1) An electronic device with three connectors that can be used for switching or amplification. Invented at Bell Laboratories in 1947, transistors are simple semiconductor devices that provide an inexpensive, low-power replacement for the bulky, power-consuming and unreliable vacuum tubes that were used previously for amplification and switching purposes in electronic circuits.

2) There are many different types of transistors. Some are designed to amplify an electrical signal and some are designed to switch “on” or to switch “off.” Transistors that amplify are used in inside audio amplifiers. They can power loudspeakers or headphones so one can listen to an audio program. A transistor that only switches is used inside things like power supplies and computers.






TRANSMISSION PROTOCOLS:       In digital audio and visual computer processing, “transmission” means the sending of digital information from one piece of equipment to another. A “protocol” is a set of rules and guidelines used by computers to communicate with one another. Some digital audio equipment has different combinations of audio connections to send and receive data. On the backs of such equipment commonly may be found four AES/EBU connectors (XLR connectors). Different combinations of these connectors are used to send and receive digital audio data, depending on the sampling rate of digital audio information. There are three basic combinations of connectors used:      “single,” “dual” and “wide” (also called “quad wide”). Each of these combinations is for 2-channel stereo audio program. “Single” protocol uses one AES/EBU connector and one wire to transmit audio having a sampling rate of 44.1 or 48 kHz. “Dual” protocol uses two connectors (and two wires) to transmit sampling rates of 88.2 or 96 kHz. “Wide” (or “Quad Wide”) is the protocol for digital audio having sampling rates of 176.4 or 192 kHz, in which case all four of the connectors are used.


TRANSPARENCY, TRANSPARENT: A desirable property of a sound system. Audio that is “transparent” sounds very natural and has no indication that it is being played through electronics at all. It’s like the electronics aren’t there and one is just listening to the sound as it occurred in the physical universe - in the air. No hint of electronics at all. The equipment seems to disappear.


TRANSPONDER1) There are many individual electronic receivers inside a communications satellite, such as those used for television broadcasts. They receive a signal sent from an Earth station, and send it back over a very wide area for reception. The unit inside the satellite that receives is called a “transponder” because it responds to a transmission sent from Earth. It then relays that signal back, enabling a large area of the planet to pick up the broadcast. When Gold broadcasts events over satellite the “transponder” is announced - meaning the orgs are told which transponder to tune into to receive the event. For example, a satellite may have a number such as “T4” but its transponder handling our event may be #22. So the orgs are told, “Tune into T4 channel 22.” Transponder and “channel” are used interchangeably. The org event satellite personnel know to tune to “Telstar 4” (T4) channel 22.

2) A radio or radar receiver or transmitter that automatically sends out a signal of its own once it picks up a signal from another location. Such a device is often used to locate and identify objects.


TRANSPORT SYSTEM:       In a tape recorder, video deck or projector, the system of motors, tape guides, etc., used to move tape through the machine. It’s the parts of a tape deck that move the tape, including the motor(s), hubs, capstan(s), pinch roller(s), and other mechanisms. In a compact disc player, the transport system rotates the disc.


TRANSPORT (CD):     A unit that looks like a CD player but no actual sound 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 another unit that processes the CD’s digital signal and creates audible sound. A CD transport is always used with this other unit (a digital to analogue converter).


TREATMENT:       1) A “treatment” is a written detailed outline of a motion picture, television program, radio script, etc. In addition to writing many complete film scripts for the tech and public films, LRH wrote 50 treatments for the Public Scientology Motion Picture Series. 2) See SOUND TREATMENT.


TREBLE: The higher audio frequencies, roughly 2 kHz or above. Treble sounds include cymbals, twinkling of bells, the higher notes of a trumpet, etc.


TREBLY:        Too much treble. The high frequencies are too loud in comparison to the rest of the sound.


TREMOLO:    An audio special effect such as guitar sounds that have rapid vibrating beats or pulses throughout the tune. That is an effect on many guitar amplifiers, called “tremolo.” It literally makes the sound rhythmically tremble.


TR FILMS:     See TECH FILMS for full listing.


TRIM, TRIM KNOB, TRIMMER:       A volume control inside audiovisual equipment, on a mixboard, etc. It allows one to “trim” (make adjustments in) the amount of any signal which passes through the trimmer. 


TRIGGER, TRIGGERED:    To tell some other piece of musical equipment or audiovisual gear to start an operation. One piece of gear or a signal from an operator can “trigger” the desired function to activate.      


TRINITRON:        A long standing Sony trademark name for their television sets. (“Trina” means three; there are three colours which make up all colours seen in a TV - red, green and blue.)


TRIODE, TRIODE AMPLIFIER:       See PENTODE for full details on all vacuum tube amplifier types.




TRUCK (the):      The travelling complete facility for video and audio housed inside a truck trailer, often used for live event recording and broadcasting. It provides all audiovisual for those receiving the broadcast, and for the live audience outside the main hall in overflow areas. The truck also contains all event communication facilities (radios, etc.). Also called a “production truck.”


TRUCK AUDIO:    For most televised and-or pre-recorded live events, there is a large production truck parked outside the hall. This truck acts as the technical control centre. It also houses most of the audio and video recording and playback equipment. In the truck, an audio booth exists where there is a mixing engineer, an assistant, a mixboard and much other mixing equipment. The event’s sound is mixed there for the live broadcast, overflow areas and the Green Room. The pre-recorded audio for the event (such as music to play during the event) is also routed to the event hall via the truck audio mixboard. This production area for an event is referred to as “Truck Audio.” It is an entirely different line than the “House Audio” line where the house audio Mixer controls the live sound for the audience in the event hall.


TRUNCATE, TRUNCATED, TRUNCATING:    “Truncate” means to shorten by cutting off; from the Latin word meaning, “to lop” (like to “lop off” - to cut off). In the digital audiovisual and computer fields it means… 1) To shorten the length of a digital word. An example of this is a digital audio recording made on a 24 bit recorder being played back on a 16 bit machine. The 16 bit machine would cut off (“truncate”) the 24 bits of the 24 bit recording and reproduce only 16 bits. 2) To down-convert a digital audio signal from a higher bit rate to a lower bit rate. Done when preparing a digital recording done at 24 bits for CD release which requires digital information to be 16 bits. A converter would be used to “truncate” the 24 bit music down to 16 bit music. 3) Another example of truncation occurs when recording a live sound, like a snare drum, onto a computerised musical instrument. One invariably captures a bit of the “dead” time before the note occurs, and some time after the sound decays. Truncation would thus involve deleting the dead time at the beginning of the sample (so the drum will sound as soon as a keyboard note is pressed) and doing the same at the tail of the sound. 


T-STOP: “T” stands for “Transmission.” A “stop” is a notch that you can feel as you move the lens aperture adjustment up and-or down - when you feel that notch you can be confident that the setting is at the exact stop indicated by the number at the notch. “T-stop” is a scale of numbers that corresponds to the amount of light actually transmitted by a camera lens. This term came into use in the field of photography in the late 1950’s. A lens setting with a low-numbered T-stop transmits more light than one having a larger T-stop number. The lower the T-stop number, the more light the lens will transmit. T-stops measure the amount of light which is transmitted through a lens. F-stop numbers designate the amount of light that reaches the lens, but do not take into account the absorption and reflection of light done by the lens elements themselves. T-stops designate the exact amount of light that actually is transmitted through the entirety of the lens and finally reaches the film. When a lens is manufactured, the T-stop numbers are calculated by a precision electronic light meter and the lens is rated in accordance to the measurement. Most professional lenses are calibrated in reference to T-stops and the stop numbers written on the lenses are actually T-stops - even though they are often referred to as f-stops. 




TTAPP:  An abbreviation for Tape Transcription Archives Preservation Project. TTAPP was also known as the “tapes to books project.” This project was done in the mid to late 1970s to preserve and make available, in written form, all LRH lectures.


      TTL:        An abbreviation for Transistor to Transistor Logic. The word “logic” as used here refers to the two-valued “logic” of a digital computer electronic circuit. A computer logic circuit’s values are “on” and “off.” The transistors in a TTL circuit produce two different values (voltages) of electrical flow. For example, 5.0 volts and 0.2 volts, where the 5 volt signal = “on” (or the digital value “1”) and .2 volts = “off” (or the digital value “0”). The standard values in a logic circuit are that any voltage from 2.0 volts to 5.0 volts = “on” (“1”) and any voltage less than 0.8 volts = “off” (“0”). Many different types of computers and computerised equipment use TTL circuits in performing their operations.


TUBBY:  Having an exaggerated bass range. Bloated. Having low frequency resonance.



TUBE:     Short for vacuum tube. A sealed glass or metal tube evacuated of air or filled with gas at low pressure, used to amplify a signal.


TUBE ELECTRONICS: Any audio electronics that uses tubes.


TUNE UP (an audiovisual device):       1) The action of calibrating and adjusting for optimum performance any electronic device. 2) A term used to describe the process of setting up a loudspeaker system and then doing various tests and playing well-known sounds and music to ensure their performance is made perfect. Even slightly moving a speaker can improve its sound. Just like a car can be tuned up for best performance, so can a loudspeaker system. Tune up is done before any event or show and it is also done for studio loudspeakers and anywhere high quality sound is desired.


TUNING FORK:   A metal fork with two prongs that, when vibrating, put out a pure tone of one frequency. Piano tuners use these to generate an exact pitch as a stable datum.




TURNTABLE:        Also known as a phonograph or record player. It is called a turntable because it has a platter which turns round and round upon which the record to be played is placed. (The platter is called “the turntable,” but the term quickly grew to mean the entire phonograph player.) A turntable is for playing vinyl records. The platter spins a record around at an exact speed.




      TWEAK: A slang term for calibration, especially very precise and intricate adjustments. 1) To fine-tune a system or component. 2) To do fine adjustments to a mix to improve its sound. 3) To do fine adjustments to a microphone to improve a recording.


TWEAKER:    A little screwdriver used in electronics to adjust small parts. Tweakers are made to fit snugly into or over the adjusting screws in electronic equipment and not slip out.


TWEETER:    A loudspeaker specifically designed to only reproduce high (treble) frequencies. There are several types of tweeters, some have ribbons as their diaphragms, others a hard plastic, while others have a metal dome for a diaphragm




TWO WAY PAGER:     A pager that is capable of having the user actually answer a page, letting the sender know the message was received.


TWO WAY SPEAKER: A loudspeaker that consists of two drivers (woofer and tweeter) and a crossover that enables each to reproduce a selected range of frequencies.


TYMPANI, “TYMPS”:  A large set of drums used in orchestral-type music. They are made of brass or copper. Tympani are also called Kettle Drums. Comes from the Latin word meaning, “to beat or strike.”


TYPE I, TYPE II, and TYPE IV:      On some Nakamichi models the “tape selector button” on the Standard Tech Cassette Deck has buttons for “TYPE I”, “TYPE II” and “TYPE IV.” (There is no TYPE III made.) These selectors are for recording and playing back the different types of cassette tape. Tape Type I is ferric tape. Tape Type II is chrome tape and tape Type IV is for metal tape.