Compressor Timing

[SoundSnob]

Has anyone got any tips on grooves for electronic(techno, hiphop ,trance) music with compressors?i use three main drum machines 808, 909, mpc mixed on a mackie.should i compress all the drums together before final mix compression with other analouge sounds?
how does a compressor improve a sound like an 808 kick?i remember rick writing that compressors act like glue,wich helped me alot in thinking about audio getting stuck to the volume envelope of louder sounds triggering the compressor.Am i on the right track?so how do they fatten sounds up?

[chris p]

OK, compressors 101:

1. Compressors reduce the dynamic range of their input - they lessen the difference between the loud sounds and the soft softs. Usually, by quieting down the loud bits. That's why they usually have a make up "gain" or "output" knob to turn the whole bit of music up again.

2. So, subject to point 5 below, there's usually not a lot of point in compressing the individual electronic drum tracks (esp. from the 80's vintage 808 type machines) - there's not much dynamic range in their sound to start off, so there's not much to compress. Think of the difference between the electronic gated crash cymbals on the drum machine "Gshshshshshsht" and what happens in real life when a drummer hits a crash "KhSHSHSHSHshshshshshshshhshshshshsh.......". Compressing the real cymbal tones down the transient attack and makes the tail longer. You also get an increase in loudness of all the harmonics. This makes it sound fatter and more rounded. Compressing the former, where there's no tail and precious little harmonics, doesn't change the sound nearly as much.

3. As for compressing the drum tracks together, again the question is whether there is dynamic range there to be compressed. 808 Closed hi-hat sounds tend to be quieter than the kick and snare, so compression will bring them out more, if that's what you want. You may prefer them the way they are. Same comments apply to drum mixes.

4. As for compressing the final mix, that's a topic of more art than science. I defer to the experts on the forum for comment.

5. There's an important qualification to all this: No compressor is linear across the full frequency and dynamic range. This has two interesting effects. First , when the input source is turned up all the way, the compressor is working overtime to compress it to the max most, if not all, of the time. It is in fact acting more like a limiter by flattening out the two extreme ends of the sound wave, and this has audible effects on the tone. You may well want to apply this crunched sound to an individual drum track, although like everything it is better used as a seasoning and not a sauce - use it lightly rather than smothering everything.

Secondly, with the right gear the distortion in the non-lineral regions can add a nice air to the tone - even when not actually compressing the sound that much. This is where you get the debate of valve vs VCA vs optical compression - each sounds good when used in the right context, but which is right for you depends on how you want your music to sound. In very rough and meaningless generalisations, valve = warm, VCA = crunchy, optical = airy.

Man, that's so much more than I was going to say when I started all this. Hope it helps.

[heathen]

Making drums appear more punchy with a compressor lies in the attack and release settings,the more transiet you want to let through the slower you should set your attack (roughly 10 ms)and faster your release (70 - 80 ms) to avoid residual compression on the next hit,it's all in the timing of the music really.. Guitars I will usually give a slower attack and a slower release as the loudest part of the sound takes longer to build up. The main thing to remember about a compressor is it's actual definition,they are amplifiers who's output decreases as it's input increases.
Hope that helps a bit.