Sidechaining refers to the practice of using the signal level of an input to control the compression level of another signal. When the external signal is stronger than a specified amplitude (threshold), the compressor acts more strongly to reduce output gain on the sidechained track. It is useful in a variety of situations including:
- Creating a pumping effect in electronic music
- Automatically lowering a signal in audio post production
- Automatically lowering music while speaking into a mic
I will demonstrate here a basic application of sidechaining between a synth bass and a kick drum to achieve the characteristic pump in an EDM track.
Add a compressor to the bass track. We are going to use the kick to control the compression level of the bass.
Activate the compressor’s sidechain input.
On the kick track inspector/console- click “+” to add a send. Choose the bass compressor from the list of available sidechains.
Note that, although the compressor is on the bass track, it is responding to the kick drum signal.
Now you can adjust the threshold and ratio of the compressor until it you achieve the sound you’re looking for