
Surround Compressor Main parameters in Logic Pro for Mac
The Surround Compressor Main parameters set compression and output values.

Main parameters
Ratio knob and field: Set the ratio of signal reduction when the threshold is exceeded.
Knee knob and field: Set the ratio of compression at levels close to the threshold.
Attack knob and field: Set the time it takes to reach full compression, after the signal exceeds the threshold.
Release knob and field: Set the time it takes to return to zero compression, after the signal falls below the threshold.
Auto button: Turn on to dynamically adjust the release time to the audio material.
Limiter button: Turn limiting for the main channels on or off.
Threshold knob and field: Set the threshold for the limiter on the main channels.
Main Compressor Threshold sliders and fields: Set the threshold level for each channel, including LFE, which also has independent controls.
Main Output Levels sliders and fields: Set the output level for each channel, including LFE, which also has independent controls.