How to compress drums on the drum bus

Single drums first, then the bus

Drum compression happens in two places, on single drums and on the drum bus, and they do different jobs.

On a single drum, a compressor shapes that one sound. A kick that sounds soft can get more punch from a slower attack that lets the click through. A snare that varies a lot from hit to hit can be evened out. Fix those first, on the drum's own track, because a problem in one drum needs a move that only that drum should get.

On the drum bus, a compressor works on the whole kit at once. Its job is to move the drums together, so a loud snare hit pulls the cymbals down a touch and the kit breathes as one instrument. That is what people mean by glue. The bus stage on this page uses the RMS detector at 2:1 to 4:1 with a 10 to 30 ms attack, and aims for only 2 to 4 dB of gain reduction. Small amounts do the job.

Send every drum track to one group in Live, and put the bus compressor on the group. Then you can still change the level of each drum underneath it.

Glue or punch

The attack decides whether bus compression adds punch or takes it away.

With a slow attack, 10 to 30 ms, the front of each hit gets through before the compressor reacts, and then the compressor turns down the ring that follows. The hits stand out more against the tails, so the kit sounds punchier. This is the usual starting point on a drum bus.

With a fast attack, the compressor grabs the front of each hit and flattens it. The kit sounds smoother and further away. That can suit a soft track, but on most drums it is the quickest way to lose the punch you came for.

The release shapes the groove. Set it so the meter falls back toward zero before the next beat. Too slow and every hit starts already turned down. Too fast and the cymbals swell up between hits. A release that pumps in time with the tempo can sound great in some styles, so let your ears decide whether it helps the track.

If the kit needs more weight than a gentle bus stage gives, don't push the bus harder. Use parallel compression instead. A heavily compressed copy of the kit, blended in under the dry one, adds body while the dry kit keeps its punch. The optional stage on this page does that with a fast attack and a lot of gain reduction, mixed in at about a third.

Electronic drums and live kits

A live kit has the most to gain from compression. Every hit is a little different, the room sound ties the drums together, and bus compression brings up that room and makes the kit sound bigger. A gentle bus stage and a parallel copy are the classic pair.

Electronic drums are often already even, because every hit of a programmed kick plays at the same level. Bus compression on them is less about leveling and more about tone. A small amount glues the kick, snare and hats into one groove, and a release timed to the beat adds movement. If the drum samples are already squashed, use even less, or skip it and see whether you miss it.

Many electronic tracks also duck other parts with the kick, using a sidechain. That is a separate job from bus compression, and it sits on the parts being ducked, not on the drums.

Mistakes on the drum bus

Too much gain reduction is the main one. When the meter moves a lot more than 4 dB, the kit starts to sound flat and lifeless, and the cymbals turn into a wash. Raise the threshold until the meter only moves on the biggest hits.

Fixing one drum on the bus is the next. If the snare is too loud, turn the snare down. A bus compressor working hard to hold one drum back squashes everything else with it.

Judging louder as better catches everyone. Makeup gain makes the kit louder, and louder sounds punchier at first. Match the level before you compare.

Forgetting the low end is the last. A big kick can drive the whole bus compressor, so every kick pulls the rest of the kit down. If the kit pumps with the kick when you don't want it to, ease the threshold, or turn on the compressor's sidechain EQ and filter out some of the low end it reacts to.