Studer OnAir 500 Modulo, Operating Instructions Manual

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OnAir 500 Digital Mixing Console
6-2 Dynamics
Date printed:
30.07.04
6.2 Compressor
A compressor is a device that acts almost like an “automatic hand” placed on
a channel fader. It can reduce the level of signals that are too loud thus pre-
venting signal overload. This is achieved by setting a threshold level,
whereby signals that exceed this threshold are reduced (
compressed ) by a
pre-determined amount (the ratio setting). Signals falling below the thresh-
old level will pass through unaffected.
A typical example of this would be compressing the DJ microphone to avoid
sudden jumps in output level if the DJ moves too close to the microphone.
Compressor Parameters: Knee
The knee setting determines what the transition between the uncompressed
signal and the compressed signal is going to be . If Knee: HARD is chosen,
then at the point where the signal passes through the threshold point, com-
pression will begin immediately. If
Knee: SOFT is chosen, then compres-
sion will begin slightly before the point at which the signal passes through
the threshold point. The
Knee: SOFT setting will usually make the transi-
tion between uncompressed and compressed states sound more subtle and
natural.
Threshold
The threshold level determines the point at which compression begins to
occur . Signals that are above the threshold setting will be compressed ac-
cording to the setting chosen in the ratio menu. Signals below the threshold
level will pass through unaffected.
Ratio Once the signal has exceeded the threshold level, it will be reduced (com-
pressed) by the amount set using the Ratio setting . If for example a ratio
setting of 5:1 is chosen, a change in signal level of 10 dB above the threshold
will result in only a 2 dB change in output level.
Attack
The attack time determines how fast the compressor will start to act once the
signal has passed the threshold point.
Release
The release time determines how fast the compressor returns to its normal
state once the signal has dropped back below the threshold point.
Makeup The makeup control is used to increase the output level of the compressor.
Adding compression will normally reduce the average level of the signal.
The makeup control allows for this level drop to be compensated.
Compressor Display:
When a compressor (or limiter) is assigned to a channel and the DYN button
is pressed, the input display will show gain reduction by illuminating the
blocks in its upper line from left to right .