Compressing drums – why?
Compressing drums seems to be a process many mixing engineers reach for more or less by default. Even the so called big name guys. It’s understandable, because most of us want drums to sound big, in your face, and earth shatteringly enormous. It’s all fine and dandy, so where is the problem? – you may ask. Well, my friend, you wouldn’t believe it, but we can indeed run into a problem with compressing drums.
That bigness, that is in danger, when one turns to compressing drums. Without executing a couple of tricks, at least. Because compression will kill your transients. The harder you compress, the more it will do so. That’s the reason why in many cases – even on some famous albums – the drums are punchy and rumbly, but at the same time they are small and weak as well. Compression can bring out part of the bigness, with turning up the level of ambience. It means all the sounds and noises surrounding the main sound, ones that are normally less audible (if you weren’t recording in a metallic room or a cave), will come up in volume. But at the same time it will render the impact of the attack transients less prominent.
So what can we do, if we want to preserve both of these sonic attributes, without the negative effects of compressing drums? There are a couple of options we can try. One of them is to only compress either the overheads, or – if you used them – the room mics, or both of them. You can leave the spot mics uncompressed. This will bring up as much tasty “rumble” and as needed, without compromising your precious transients.
An alternative method is to use parallel compression. Right on the spot mics, and/or on the drum bus. It can be done with either setting the wet/dry ratio on the unit (if you have such option), or placing the compressor on an aux send. You need to be more careful with this technique, cause you can easily set the compressed ratio too high, masking most of the transients this way. That will render the drum hits just as powerless as if you used full on compression.
A third way to get around the problems of compressing drums is to use our good old friend: distortion. It’s actually a pretty good workaround, with surprisingly good sounding results. Saturation/distortion has an evening effect as well, but it can preserve a good amount of the impact as well. It’s because of the frequency dependent, nonlinear nature of distortion. Choosing the right method or their combinations, and experimenting with additive (parallel) processing will surely give you great results.