Demystifying Audio Compressors – How to hear what they’re doing!
Audio compressors can be a daunting tool for beginners, however it’s an essential tool in any audio engineer’s arsenal.
Knowing what to look for and how to use them, can make or break any production.
So, let’s demystify the compressor a little bit for you! Today we look at a technique to quickly assess what a compressor is doing to your transient response and dynamic range. The idea is to squash down your audio source by reducing the threshold way down and increasing the ratio way up, then to accentuate the effect, we increase the make-up gain. This over-exaggerates what the compressor is doing, making it much easier to tell its “character”.
Now you will immediately be able to tell the difference in transient response that’s applied to your signal when you adjust the “Attack” and “Release” parameters of the compressor.
The idea is to find your desired transient response or “punch” and then dial back the “Ratio” and “Threshold” parameter to decrease the exaggerated effect. The result is full control over every parameter and being able to tell what it’s actually doing to the source – removing a large amount of the guesswork associated with compressors.
Audio compressors can be somewhat of an A.R.R.T.form…
There is no right or wrong way to do it, some genres call for much heavier compression than others.
You wouldn’t apply the same settings on an acoustic guitar as you would on a hard house bassline, so it’s important to be able to know what to look for and be able to apply your knowledge accordingly.
There’s an acronym that helped me remember this technique – A.R.R.T or A.R.T.R.
It stands for the sequence in which you apply changes after the initial “squashing”.
Attack, then Release, then Ratio, then Threshold.
Here’s a quick video outlining the technique, and discussing the different characteristics of different styles of audio compressors:
