Hey Michael!

Honestly, this is something I have to learn more myself. As I often say.. compression is the trickiest tool to learn in audio production, but the most fun and rewarding.

(Those reading.. please view my Why Do We Producers Use Compression [COURSE])

Between EQ and Compression, I think compression actually gives you the most control over your audio (especially if using a multi-band compressor). It is amazing how much you can control a sound, whether that be an individual sound, or on the master track.

To answer your question, I truly do think it is based on the samples and presets you are you using.

The biggest thing that will help you decide of a fast or slow attack on a compressor is having a fair volume comparison, especially in these cases, as we’re focused on truly changing the impact of the drum.

If we have a fast attack (it squashes the transient of the drum), it is trying to keep the tail of the drum more even with the initial hit. So we lose that “hard hit”.. But, you will notice the “sustain” (or its tail) will actually be louder now, and may stand out in the mix!

Sometimes the easiest solution I have found in later years is to just use parallel compression, as we kind of get the best of both worlds.. you get the transient (for a hard hit), but the parallel track brings up the tail for a more audible drum.

If you are using sidechain compression on the kick drum and bass, if they both have a longer attack where the transient is popping through, then that would not matter, as the sidechain compression is correcting any issues that would happen when they both play (if the kick drum is routed to turn down the volume of the bassline).

In terms of the release, people often say to look at the gain reduction meter and try to get it to “pump with the song”.

When it comes to a kick or bassline, I think that advice has lots of value, as we want to hear those low-end frequencies, and too long a release can hide the bass frequencies from standing out.

However, the release I think of as “control”. Even if that release is a little long and doesn’t “pump with the song” all the time, it may be used to help even out the individual sound, or the overall master, as it plays.

If the release is too long, note that the when the sound initially plays, there may be an aggressive hard transient, but as it continues to play, the compressor will not let go and “control” the audio, which can be pleasing..

In summary, I do think the attack on a compressor is sample dependent. I often think “do I want it to hit harder?” (longer/slower attack). Or.. do I want to hear the drum LONGER in the mixer.. (faster attack).

It’s hard to give numbers, as every compressor is different, as well as each sample.. but for fast I’d say anything under 15-20ms.. and over that is when you’ll start noticing the transient pop through more, for that harder drum hit.