Sidechain¶

The Composer; compressors, limiters, expanders, gates, and duckers have sidechain inputs. In any Symetrix dynamics control device, (analog or digital), there is an audio path and there is a control signal path. The control signal path represents the conversion of the audio signal level into a gain control signal. In most dynamics devices, the input signal is also the input signal to the control signal processor.

A useful tool is the ability to modify the signal used by the control signal processor. For many dynamics devices, modifying the frequency response of the sidechain signal can help prevent extraneous signals from causing unwanted gain reduction.

• A compressor with its sidechain signal driven by a split from a microphone signal, reduces its gain in response to the microphone signal level; a rudimentary ducker.
• Putting a highpass filter in series with the sidechain signal into a compressor can help prevent the compressor from punching holes in the signal in response due to a P-Pop into a microphone and aggravated by proximity effect and the bass response of the microphone.
• A gate, with its sidechain (or key) signal driven from another source means that the key signal must be present for the gate to pass its signal.

The Composer sidechain connections are unique because they auto-detect when there is a signal connected to their sidechain input. If you connect nothing to this terminal then the sidechain gets it's signal from the input terminal. Connect something to this terminal and that signal is the sidechain signal.