Here’s Part 3 of our series on compression.
There are a couple of less conventional uses for compression that are discussed a lot, so I thought it might be good to give some advice on them and dispel some myths.
I’m talking about parallel compression and side-chain compression.
This is simply the process of running a compressed signal in parallel to an uncompressed signal.
The most common use is on a drum bus, so you can have an uncompressed (or very lightly compressed) main drum bus that all your drum sounds are going through, and alongside it you’ll have a heavily compressed signal that all those same drum sounds are going through too.
This can be a pretty useful technique as it allows you to really smash and over-compress a signal (a cool sound in the right situation) and then subtly feed that into your mix, as much as you want. If you have a compressor with a ‘Mix’ control this effectively allows you to parallel compress, as it adjusts between the compressed and uncompressed signal with that knob.
Quite often I prefer feeding just some elements of the drums to the parallel compressor – for example just the kick and snare, or sometimes the toms as well.
As always, try different combinations in a mix and see what sounds best to you.
This is a really useful technique for adding dynamics to something that doesn’t have any.
For example, you might have a pad that doesn’t move or change and you want it to be a bit more interesting. You could compress it but have the sidechain fed by your drum bus – or just the kick / snare maybe – and then your otherwise static pad is moving with the rhythm of the track.
One thing that side-chain compression is not ideal for is making two elements sit together in a track. Because that’s not what you are actually doing – you’re turning one down whenever the other sound comes in.
I know a lot of people will side-chain the bass to the kick drum but imagine telling a bass player that you’re going to turn him/her down every time the drummer hits the kick drum. You run the risk of a heavy guitar flying in your direction!
If you want elements to sit better in a mix together then reach for the EQ, not the side-chain compression.
Check out the other parts of this series: