AV Expert Glossary

A
AC3

Dolby Digital, or AC-3, is the common version containing up to six discrete channels of sound, with five channels for normal-range speakers (20 Hz - 20,000 Hz) (Right front, Center, Left Front, Right Rear and Left Rear) and one channel (20 Hz - 120 Hz) for the subwoofer driven low frequency effects.

Amplifier

A component that increases the gain or level of an audio signal

Aspect Ratio

The aspect ratio of an image is its displayed width divided by its height (usually expressed as "x:y" with the joining colon or multiplication symbol articulated as the preposition "by" or sometimes "to"). Currently, the most popular standard ratios are the anamorphic (2.39:1)[1], the traditional 4:3 (1.33:1), still used for many television screens, and its modern 16:9 (1.78:1) successor, used in high-definition television and European digital television.

B
Bi-wiring

Bi-wiring is a means of connecting a loudspeaker to an audio amplifier, primarily used in Hi-fi equipment. Normally, a single cord (two conductors) runs from the amplifier output to the terminals at the loudspeaker housing. From this point, connections are made to the loudspeaker elements - most often through crossover networks. In bi-wiring, two cords are run from the amplifier output to the speaker cabinet - one to the high frequency or tweeter element and one to the low frequency element (through their respective crossover networks).

C
CD

A Compact Disc or CD is an optical disc used to store digital data, originally developed for storing digital audio.

CD-R

A CD-R (Compact Disc-Recordable) is a variation of the Compact Disc invented by Philips and Sony. CD-R is a Write Once, Read Many optical media (though the whole disk does not have to be entirely written in the same session) and retains a high level of compatibility with standard CD readers (unlike CD-RW which can be rewritten but has much lower compatibility and the discs are considerably more expensive).

CD-RW

Compact Disc ReWritable (CD-RW) is a rewritable optical disc format. Known as CD-Erasable (CD-E) during its development, CD-RW was introduced in 1997, and was preceded by the never officially released CD-MO in 1988.