Now we are going to learn the basics of how to use a compressor: What it is? How it works? When you should use it?
The most simplest way to explain what a compressor does: It makes loud peaks quiet. Of course, with certain settings you can change the characteristic, the feel, the coloring and all these kind of things. Let’s find the basics so you can avoid from the worst mastering mistakes.
Why do you actually need to learn how to use a compressor?
Regarding it’s making loud parts quiet it’s extremely handy to use it if you have audio files that has big dynamic range. Of course, your audio material could have parts which are very quiet and at several points it’s too loud. Basically the compressor makes the high parts lower so they will be closer to the low parts in volume. So you can get an audio file which more “equal” and more satisfying to listen to. Also you will be able to achieve the perfect loudness which is crucial especially in EDM and Future House tracks.
It’s the same thing when you are watching a movie and the effects are twice as loud as the previous dialog was. That also really hurts you, but those are made for purpose. In music, it doesn’t necessary.
The most important thing to set on a compressor is the threshold
With threshold you can set the level at which the compressor will be active. When it works, it will reduce the volume of everything above the threshold level. For example when you set it to -2 dB, then everything above -2dB will be compressed. Of course nothing can be above 0dB so this setting doing nothing.
That’s the first part of compression but there are a lot more settings you should know about than just threshold, like ratio, makeup gain, attack and the release.
Attack and release
These settings are also quiet simple to explain. Attack is how it actually takes when the threshold is detecting an audio signal to lower it. That means if you set attack long that needs a little bit of time to do the compression. Release is basically do the same as attack, but reverse. It does the trick at the end of the audio signal which going above the threshold level. It sets how long does it take to go back to the normal parts which are uncompressed because it’s under the threshold level.
Ratio is actually setting how much it’s doing all above I mentioned. The higher the ratio the more the compressor does.