Compressor side chain parameters in Logic Pro for Mac
Compressor side chain parameters are shown to the right when the Side Chain button is active.
You should note that side chain parameters are active even if no external side chain source is selected. As with hardware VCA compressors, the (compressor) audio input is “normal-ed” as a side chain source when no external side chain signal is patched.
Note: Not all parameters listed are available in each Compressor model.
Compressor side chain parameters
Detection buttons: Choose the way stereo side chain signals are handled at the side chain input.
Max button: Turn on to compress both channels if either stereo channel exceeds or falls below the threshold.
Sum button: When enabled, the combined level of both channels must exceed the threshold before compression occurs.
Peak/RMS buttons: Use in conjunction with the Max and Sum buttons. Choose Peak or RMS to determine whether signal peaks or a signal average is used for detection. These can help with avoiding artifacts such as clicks in the processed signal, depending on the type of audio material and parameter settings (notably Attack).
Filter buttons: Turn the filter on or off. Turn on Listen to monitor the side chain signal.
Filter mode knob: Choose the type of filter used to process the incoming side chain signal. Filtering the side chain input signal can enhance the precision of trigger signals, resulting in more surgical compression. The choices are LP (lowpass), BP (bandpass), HP (highpass), ParEQ (parametric), and HS (high shelving).
Frequency knob and field: Set the center frequency for the side chain filter.
Q knob and field: Set the width of the frequency band affected by the side chain filter.
Gain knob and field: Set the amount of gain applied to the side chain signal.