Only the very best drummers can hit the drum the same every time, so using compression is almost a necessity. Proper compression can bring up the lows and help deliver solid drum sounds. Commonly, drums can be compressed more than other instruments because they are less musical and more percussive. Overdo it, though, and risk diminishing the impact of the drums because the low-end can’t really push the speakers. You don’t get that thump in the chest no matter how loud you turn it up.
Try these starting points:
Attack. Start with a fast attack, 5-10 ms or maybe faster. A slower attack time can allow initial peaks to sneak through before the compression kicks in. This may give a nice added crack to a snare sound, but watch for overload. Set the attack time slower on the kick drum, as it may take a few milliseconds to build to its full potential. Fast attack and release times bring up the body of the drums and cymbals. An attack set too fast may diminish the initial crack of the drum.
Release. Start at 250 ms, then move to suit the song. A fast release time can bring up the level of the decay and raise the sound of the snares.
Ratio: 3:1 or 4:1. Drums, due to their nature, have fast natural attack and release times, with plenty of peaks. A high ratio levels the dynamics while delivering the meat of the sound. Control the signal enough to record it, yet don’t over compress it so as to lose the initial transient crack. Of course, as the ratio gets higher, past 8:1 or 10:1, the compressor becomes a limiter. A limiter is great for eliminating transient overload on digital input circuits.
Threshold. Low. A lower threshold preserves the full impact of the drums, and can sustain the cymbal’s natural decay.
Tim Crich wrote the bestseller Assistant Engineers Handbook. He has over 20 years of experience in the recording studio, and has worked on records by Rolling Stones, Bob Dylan, John Lennon, KISS, Billy Joel, Bryan Adams, Cher, Bon Jovi and many more. This article is excerpted with permission from his new book Recording Tips For Engineers, available through www.musicbooksplus.com. For more information, see www.aehandbook.com.