A/V is an abbreviation for Audio/Visual

A CD+G is a specially formatted disc that has an additional line of sub-code on the CD that is responsible for the lyrics that play on video screen for Karaoke systems. CD+G stands for Compact Disc + Graphics.

Refers to a type of distortion that occurs when an amplifier is driven into an overload condition. Usually the "clipped" waveform contains an excess of high-frequency energy. The sound becomes hard and edgy. Hard clipping is the most frequent cause of "burned out" tweeters. Even a low-powered amplifier or receiver driven into clipping can damage tweeters which would otherwise last virtually forever.

Named after Alexander Graham Bell. We perceive differences in volume level in a logarithmic manner. Our ears become less sensitive to sound as its intensity increases. Decibels are a logarithmic scale of relative loudness. A difference of about 1 dB is the minimum perceptible change in volume, 3 dB is a moderate change in volume, and about 10 dB is an apparent doubling of volume. 0 dB is the threshold of hearing and 130 dB is the threshold of pain.

Delay is also a facet of the echo process. Delay refers to the amount of time that exists between echoes.

Digital echo is a synthetically processed sound effect that mimics natural echo. Echo in general is the "bouncing" of waves back and forth between 2 surfaces. This effect gives a spacious or ambient feeling that works great with vocals.

The range of human hearing is commonly given as 20-20,000Hz (20Hz-20kHz). One hertz (Hz) represents one cycle per second, 20Hz represents 20 cycles per second and so on. Lower numbers are lower frequencies.

To increase in level. The function of a volume control.

CD players, VCRs, Laserdisc Players etc., are connected in a system at line level, usually with shielded RCA type interconnects. Line level is before power amplification. In a system with separate pre-amp and power-amp the pre-amp output is line level. Many surround sound decoders and receivers have line level outputs as well.

A speaker, (driver), used to reproduce the middle range of frequencies. A midrange is combined with a woofer for low frequencies and a tweeter for high frequencies to form a complete, full-range system.

Multiplex is a type of Karaoke software that has specially formatted left and right channels to make multiplex features available. To be formatted for multiplex use, a disc must have the vocals coded to the right channel and the music to the left channel. When you select a multiplex mode, the unit will remove the right channel (vocals) and split the left channel (music) to both sides.

When speakers are mounted in reverse polarity, i.e., one speaker is wired +/+ and -/- from the amp and the other is wired +/- and -/+. Bass response will be very thin due to cancellation.

Or Pre-amp is a device that takes a source signal, such as from a turntable, tape-deck or CD player, and passes this signal on to a power-amplifier(s). The pre-amp may have a number of controls such as source selector switches, balance, volume and possibly tone-controls.

Rack Mountable refers to the ability to place unit into professional or travel rack cases. Such cases are great for building complete systems and protect them during transportation. The standard rack size for MOST cases is 19".

Repeat is facet of the echo process. Repeat refers to the frequency of echoes within a period of time.

Sub-code is specially coded area of data used by CD+G manufacturers to produce lyrics for Karaoke video output.

A speaker, (driver), used to reproduce the higher range of frequencies. To form a full-range system, a tweeter needs to be combined with a woofer, (2-way system), or a woofer and midrange, (3-way system).

VCD is a disc formatted in MPEG-1. These discs are good candidates for Karaoke use as they have an audio and a video layer to them. VCD stands for Video Compact Disc.

Vocal Cancel is a feature that removes vocals from multiplex CD tracks. To be multiplexed, a disc must have the vocals coded to the right channel and the music coded to the left channel. When you select Vocal Cancel, the unit will remove the right channel (vocals) and split the left channel (music) to both sides.

Vocal Partner is a feature that removes vocals from multiplex CD tracks much in the same way as Vocal Cancel, but with an added "auto-pilot" function. The main difference is that Vocal Partner will only remove vocals as long as there is activity going through the microphone (singing). When you stop singing, the vocals automatically return.

Vocal Reducer is a feature that removes vocals from standard non-multiplex CD tracks. To do this, the unit compares the audio on the left and right channels, and cancels out any signals that appear on both. Most currently recorded CD’s contain the vocal layer on both sides, however some may not, leading to varying results.

Any type of connection that splits a signal into two parts. An example would be a connector with one male RCA jack on one end, and two female RCA jacks on the other end.

A speaker, (driver), used for low-frequency reproduction. Usually larger and heavier than a midrange or tweeter.