Logic's Vanilla Compressor.

It’s kind of funny, considering our target audience, that we’ve yet to do a basic intro to compressors.  It is especially important to cover when you think about how often they are used counter to their design.  In fact, men with much wiser than me have compared compressors to loaded guns pointed at your eardrums.

But I think if you take a little time to think about what they do and how, you’ll find you’ll be slamming things with loudness while doing much less damage to your tracks. Lets examine the general purpose and function of compressors.

Your compressor basically is a robot-volume knob.  It turns the volume down whenever the audio gets louder than a certain level (which you get to set).  To do this your compressor copies the audio coming into it.  The copy goes to the “sidechain” which is really the ears of your compressor.

The original audio actually gets “processed,” which means it get’s turned down by the compressor when the audio passes a certain level.

Hopefully, that’s not too confusing, but if it is just picture it like this:

How a compressor "compresses" your audio.

So it’s a little blurry, but you can see that if you audio (green) gets louder than the threshold volume (red) then it turn the audio down.  Also note, that the compressor is not “selectively” turning the loudest thing down etc.  If you’re compressing a whole mix, then it turn the WHOLE mix down during the parts that are louder than the threshold

So basically a compressor is an automated “turning down” knob.  You might wonder then, why compressors are used to get things really loud?  Well when you turn down the loudest peaks on a mix, you can turn the WHOLE TRACK up in volume without those peaks clipping.

So hopefully this made a little bit of quick sense of “how” compressors work on your audio.  Keep in mind that this isn’t the cleanest process.  If applied incorrectly, compression makes things sound weird like theyre sucking in and out.

Also if you compress too much and too hard/fast, then you’ll start to hear crunchy clipping and distortions of your audio.  Usually resulting in a nasty harshness.

That’s why it pains me to get sessions from bands and find synth tracks with compressors slamming them into incredible volumes while the fader on the track is pulled all the way down. It’s not that they’re doing anything “wrong.” In fact, if you wanted a super-compressed synth track without dynamics, which is sometimes appropriate, that’s one way to do it.  The problem is that most artists aren’t trying to create that situation – they just want the keyboard to sound louder or fuller.

In the next installment, I’ll start to tackle the basic controls on compressors.

The third section will be advanced controls/techniques like sidechaining.

So stay tuned for compressor madness, because we just scratched the surface here.

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