Glossary of Home Theater Terminology
Glossary of Audio, Video and Home Theater Terms
There is a very large vocabulary of technical and descriptive terms that go with home theater. We've included the terms that you are most likely to encounter. If you are very technically involved you may find some of the more technical terms omitted from our list.
Telecine - Device used to transfer movie film onto electronic media. The flying spot scanner is the most common variety of telecine. It has a single pixel scanner that scans over an illuminated film frame to record the proper number of pixels for the format being transferred to.
THD - Total harmonic distortion. Audio signals become distortion as they pass through electronic circuits. The amount of distortion is expressed as a percentage. Lower numbers are better, but in general the human ear cannot detect distortion less than 2%.
Three-Way Speaker - A loudspeaker that has three drivers; one each for high frequencies, midrange, and bass.
Throw Distance - Video projectors typically are rated for minimum and maximum throw distances. The minimum distance is the closest the projector can be placed to the screen while maintaining proper focus. The maximum distance is typically a recommended distance based upon image brightness.
Throw Ratio - For video projectors this ratio is the throw distance divided by the width of the projected image. A fixed throw projector can only change the image size by moving the projector closer or farther from the screen. Video projectors with a zoom feature can adjust the image size by zooming in or out, while leaving the projector itself unmoved.
THX - A playback standard developed by Lucasfilm. It is not a recording technology as many mistakenly believe. It is a rigorous set of standards for equipment used in the playback at theaters and more recently in homes.
Time Shifting - Recording a program for viewing at another time.
Tone Control - Controls for the adjustment, most often, of treble and bass.
Toslink - A a squarish connector for a fiber optic cable used for DVD optical audio output. Often the entire cable is referred to as a Toslink cable. It is also called an optical cable.
Treble - The higher frequency audio signal range, approximately 3,000 Hz and higher.
Tube TV - Refers to a CRT television, because it uses a cathode ray "tube".
Tuner - Audio: A device for tuning AM and FM radio signals. Video: A device for tuning television broadcasts. Typically the are built into another unit (such as a A/V Receiver or TV respectively), although they can be sold as separate components.
Tweeter - A physically small speaker driver designed to reproduce higher frequencies 3,500 Hz and over.
Twin Lead - A wire containing two wires widely separated in a thin flat wire use for connecting to aerial antennas. Sometimes called 300 Ohm.
Two-Way Speaker - A loudspeaker that has two drivers; one each for high frequencies and bass. The midrange frequencies are divided between the two drivers. Generally, two way speakers don't perform as well as three way speakers.
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