Compressors are fact of modern production. Super useful, but for both the beginner and the seasoned pro compression is often more confusing than you would like to admit. What is it doing? How do I use it? How much do I compress something?
Right now I can tell you the only rule is to compression is…
there are no rules.
Seriously, I wish it were as easy as “every snare set to 4:1″. How to use a compressor “properly” is more a function of taste, what you’re trying to achieve, the context of the song, genre considerations, specific gear limitation and bunch of other stuff.
But instead of throwing your hands in the air and screaming out “I give up” so loud it wakes your neighbors… here are 5 ways to help you get that sound out of your head and into the speakers.
Refresher on how a compressor works:
Audio goes in hit the threshold, anything beyond this point will be lower according to the ratio amount. The Attack and Release knobs will define how quickly this volume lowering happens.
- Quick attack will compress the transient, slow attack will let the transient move through.
- Quick release will shorten the tail, slow release will start to interfere with the next signal.
5 ways to use it:
Place it over a snare and use it to even out the hits and control the dynamics. 4:1 on a snare will start to bring the body of the sound out. Try a little too much and listen to life start to be “choked” out of it.
Using a compressor across your instrument group can often help unify musical elements together. Your drums might sound great but do they sound like one instrument? Subtle group compression can really help that drum kit feel rock solid. More aggressive compression is awesome to help lock together layered instruments. Fantastic if you’re going for a massive lead or split processing instruments.
Double them up:
No one said you could only use one compressor. Try chaining up different compressors together to control different parts of the signal:
- Take a sound and use just one compressor try to control volume, shape the attack and increase the sustain.
- Use your fader to control the volume, place a fast attacking compressor to control and shape the attack and a slower compressor to bring out the body.
Neither are wrong, but have you tried both?
Duplicate your signal on the second channel compress it hard (like 10:1) and then mix it back in. In solo this sound should be over the top and choked but when mixed back you’ll get the stability and sustain of the compressed signal but retain the transient detail of the original.
Take a look at that diagram again and notice the secondary input. This is our side-chain control this mean that rather than an internal trigger for the compressor (the incoming signal) we can use anything we feel like. Anything you want to have be automatically ducked when it plays.
- Common things to side-chain: Kick drum for bass, snare for room mics on drum kit. Ghost audio triggers (Sound you can’t hear but are setting off compression during playback.