More about compression...

There is a lot you can do with a compressor. Of course, the original idea
was to limit the dynamic range of an audio signal, and equalization was
about making up for attenuated frequencies, thus making the output more
equal to the input. It’s safe to say we’ve found other uses beside the initial
ones.
Compression is a very powerful tool for injecting some excitement and
movement into a track, but it can just as easily tame the inappropriately
hedonistic grooves or make something more intimate.
Let’s not get too technical, but we should have a look at what can be achie-
ved with the different parameters that are involved in compression.
Attack can really be used as a sort of EQ that can bring something to the
front of attention by brightening the transients. This is done by using a
slow attack (let’s say 30 milliseconds and more), which will let the first part
of the transients be pointy, a quality that is enhanced due to the later part
of the transient and sustain being pushed down.
Using a really fast attack (start at around 3 milliseconds) will substantially
darken a sound by pushing down the early part of the transients. This can
create a more mellow kind of vibe whereas the slower attack will create a
more energetic, in-your-face sound. You can achieve a similar effect with
a transient designer by adjusting the attack.
The release of a compressor can contribute similar things to the vibe of
a track. But here it’s the other way around: a fast release will inject energy
and movement. It will distort the audio signal, especially if the threshold
is way down.