Drum Track Processing: Compression Tips

This is the second installment in my series of tutorials on the processing of drum tracks. Our focus here is on compression.

I tend to use compression for two distinct reasons – to color a signal or to control its dynamic range. Hardware is better, but software can get you there as well. I won’t go into great lengths about how to use a compressor but will touch upon some desired approaches regarding drum track compression. There are four different types of compressors: Vari-mu (Delta-Mu), FET (field effect transformer), Electro-Optical (opto), and VCA (voltage controlled amplifier). For processing drums I’d recommend sticking with FET’s or VCA based designs, although you can get anything to work if you try hard enough.

First, let’s talk about color. By altering a compressor’s attack and release controls, one can alter how much sustain, attack and punch a track will exhibit. For instance, through compression of a kick (bass drum) track, you can control how much beater “click” you hear versus how much “body” and thump is heard. If you want more “snap” out of a kick, simply slow down your attack to allow more of the initial transient through. Want more “shell” or “bloom” in the kick drum track? You want to crank up the attack and slow the release. Now the initial click sound is caught and tamed while the tone of the shell is boosted. Think of this approach as a way to EQ the signal without resorting to using an EQ. You are basically manipulating the attack and sustain of the drum tracks to produce more punch or to round off transients for a softer mellower sound. Stylistically speaking, Modern Rock drum tracks seem to beg for massive amounts of compression, whereas Jazz and Folk tracks prefer to be untouched.

Ratio and threshold are also definitely important to drum tracks, but to me the key to proper compression is all in the manipulation of attack and release. If you’re using an LA2A, never mind what you just read and carry on.

Okay, so the other reason compression is employed is to simply reduce a signal’s dynamic range. For instance, let’s say you have a snare drum track that has varying intensities in amplitude (meaning the session drummer played some hits harder than others) and you want a more consistent level or placement in the track, you might want to slap a compressor on it to keep the output constant. You could also place a limiter on the snare drum track to keep from spiking into the red (overloading) while still preserving most of the original dynamics. Limiting or compressing overhead mics is a common and you may find that just a touch of compression here and there can help reign in unruly hits. If you’re looking to present a more honest and natural drum sound, then I recommend slight hints of compression at low thresholds and low ratios as the prescription of choice. Should you end up strapping a compressor across the Drum Bus, I recommend keeping the compressor in Dual Mono as opposed to linking the compressor in Stereo. Use your best judgement, but Dual Mono seems more exciting and natural – allowing the drum tracks to sort of leap out of the speaker during fills and crashes.

Remember, experimentation is key with compression of drum tracks. Have fun and be sure to read my other articles in this series which address gating, parallel compression, equalization, and other concepts.