Standard Compressor - PRESONUS Revelator io44 Owner's Manual

7.2.4 Standard Compressor

1. On/Off. Turns the Compressor on or off in the signal chain.
2. Threshold. Sets the level above which the compressor begins to attenuate the signal.
3. Ratio. Sets the relationship between the amount a signal goes above the threshold, and the amount
it is attenuated. At a 1-to-1 ratio (often written as 1:1), no compression occurs. At a 4:1 ratio, a signal
that passes the threshold by 8 dB is attenuated to within 2 dB of the threshold (dividing by four). The
higher the ratio you choose, the more pronounced the compressor effect becomes.
4. Attack. Sets the time it takes for the compressor to begin attenuating a signal, once it passes the
threshold.
5. Release. Sets the time it takes for the compressor to stop attenuating a signal once it falls below the
threshold.
6. Auto. Press to toggle Auto mode on or off. When Auto mode is active, the Attack and Release
controls become inoperative, and a preprogrammed attack and release curve is used. In this mode,
the attack is set to 10 ms, and the release is set to 150 ms. All other compressor parameters can still
be adjusted manually.
7. Soft. Press to toggle Soft knee on or off. When set to "on," compression will be applied more gradu-
ally over time when the Threshold is reached by the input signal.
Power User Tip: Very short compressor release times can produce a choppy or "jittery" sound, espe-
cially when compressing instruments that have a lot of low-frequency components, such as a rich acous-
tic guitar. Very long release times can result in an over-compressed, or "squashed," sound. All ranges of
release can be useful, however, and you should experiment to become familiar with different sonic pos-
sibilities.
8. Gain. Sets the amount of "makeup gain" to apply to a signal. Once a signal is compressed, its overall
level is often reduced. This gain control lets you bring it back up to the proper level after compression
occurs.
9. Key Filter. This sets the frequency at which the compressor will engage. The compressor will still pro-
cess the entire frequency range, but it is only engaged when the specified frequency is present.
10. Key Listen. Press to listen the signal being used to trigger the compressor, as set with the Key Filter
7.2.4 Standard Compressor 72