Alesis 1622 Reference Manual page 44

Sub Master - A Sub Master (sometimes called a "SubGroup" or "Group") is used to control the
level of several channels with the movement of only one fader. The 1622 MIXER has 2 Sub
Masters.
Tape Returns - Inputs on a console specifically dedicated to receiving the signal from a tape
deck. This may either be from a Mixdown Tape Deck (cassette, two track, DAT), or Multitrack
Tape Deck.
Transients - Extremely brief, high output audio signals, usually the attack portion of a signal.
For example, when looking at a signal meter, even though the meter of a signal may indicate an
acceptable level, the transient portion of the signal (such as a cymbal crash) can very briefly rise
far above what the meter is capable of reading, causing a moment of overload and therefore,
distortion.
Trim - A control on a mixer or console that sets or "Trims" the gain of the microphone preamp.
There is a Trim control on each Input Channel on the 1622 MIXER .
TRS - A stereo phone plug is also commonly known as a TRS plug because of the arrangement
of construction; i.e. T stands for tip, R for ring, and S for sleeve. See Figure 9.
Unbalanced Line - A circuit that uses a single wire to carry the signal voltage. Although
unbalanced circuitry is simpler to build than balanced equipment, unbalanced lines are more
susceptible to outside induced hum and noise. This is not a problem at line level where the
signal is strong and the induced hum and noise is weak. But weak microphone level signals
would suffer from outside induced hum and noise. This is why balanced lines are nearly always
used for microphone level signals. See Figure 19.
VU - VU stands for Volume Units, which is one common standard of measurement of metering
on professional audio equipment such as tape recorders and consoles.
XLR - A mating male and female jack and plug used for balanced operation and normally found
on professional audio equipment. These are desirable because of their locking feature (making
them difficult to accidentally disconnect) and sturdy construction. Most professional applications
use the 3 pin type which are a requirement for balanced operation (see Balanced), although
others with more pins are used for other applications. The 8 microphone inputs of the 1622
MIXER use XLR type connectors.See Figure 19.
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