I always used compressor during my mixing, but I admit that it’s not a long time that I truly realized the real meaning of each parameter and how I have to set them to get the right result. In this post I’m trying to explain briefly the meaning of the generic parameters that you can find on a compressor. There are a lot of different compressors out there, but the meaning of the parameters it’s always the same.
Threshold: this can be explained with the sentence “Apply the compression beyond this level”. If the signal exceeds the threshold the compression is applied. If I set a theshold of -4dB, I’ll compress every signal with a volume louder than -4dB.
Ratio: it specifies how much compression you want. It’s usually written as a ratio X:1 (2:1, 4:1, 10:1 and so on until infinite). If you set it to 4:1, for each signal that exceeds the threshold by 4dB, just 1dB will be sent to the output. For a 10:1 ratio, for each signal that exceeds the threshold by 10dB, just 1dB will be sent to the output. Higher the ratio, heavier the compression.
Attack: is the waiting time before the compressor starts to work.
Release: specifies how much time the compressor must “hold” the compression on the signal. During this time no more compression is possible, because it’s still goin on. When time is up, the compressor can compress again.
MakeUp Gain: the compressor turns down the volume, sometimes it’s necessary to compensate the volume reduction. This is the right parameter to do it. It increase the final gain as you like.
In the future I’ll try to explain how to set these parameters for different kind of tracks.