In this video tutorial, Eli Krantzberg shows you one of the creative ways he likes to use sidechain compression. He'll use Logic Pro X’s Compressor on both a guitar and a bass track, to create a subtle interplay of accents that blend with a drum groove.
First off, what exactly is sidechaining?
A sidechain is sometimes referred to as a key input or a detector input. It’s a fancy way of describing the process of getting a compressor or gate to be triggered by a source other than the audio running through the channel it is placed on.
If you place a compressor on a guitar track, for example, it is triggered by and processes that guitar. When you set an alternate or sidechain input to that compressor, it will “listen to” some other audio instead of the guitar playing through the track it is placed on. It listens to the external audio arriving at the sidechain input, and it reacts based on that incoming audio it is listening to. But, it acts upon the audio playing through the track it is placed on.
The audio that is sent to the sidechain input does not necessarily have to be heard in the mix. It only has to be present for the compressor to “hear” it. This lends itself to a lot of creative possibilities, either subtle or dramatic.
In this video, I’ll show you one of the creative ways I like to use sidechain compression to take advantage of this. I use Logic Pro X’s compressor on both a guitar and a bass track and have it listen to a quarter note pulse that is not audible in the music.
The quarter note pulse provides a gentle lilt that contrasts and fits nicely with the main drum groove, which is not based on a strict quarter note pulse. The result is a subtle interplay of accents that blend with the groove of the drums and gives more movement to the guitar and bass parts.