One improvement I made when redesigning my music machine was to add a compressor, right at the end of the signal chain, to help manage the overall dynamics. It happened to be that one-in-ten craigslist item that simply didn’t work, so I’ve been getting along without it, but the replacement arrived yesterday and I’m really glad I stuck with the idea.

Practically all the music you hear has been passed through a compressor: you can make as loud a noise as you want when you are playing an acoustic instrument, but there is an upper limit when you are playing through a PA system, and exceeding that limit will create distortion. The problem is that music can be very “peaky”, especially dance music: the loud bits, like kick-drum hits, are very much louder than the quiet bits. Turning the overall level down far enough to avoid distortion leaves the body of the mix sounding quiet and anemic. The solution is to compress the dynamic range, reducing the difference between the loudest and the quietest parts of the signal: this is the job a compressor does.

So why is this important for my music machine? When a DJ spins a record, they’re reproducing a signal that has already been compressed during the recording/mixing process. The DJ can set a nice hot level for the overall sound and rest assured that the peaks have already been tamed. I don’t have this luxury: since I’m making music from scratch, I have to manage levels by hand as I go, and I generally have to leave the overall level lower to make up for the peaks. This is fine for ambient and downtempo stuff, but when I try to play louder, thumpier, more uptempo music, I end up doing a lot of work riding the level knobs without having much to show for it.

The compressor, then, lets me delegate one more tedious job to a happy little robot, yielding a clean, consistent, punchy sound. And it works! I fired it up this morning and spent a few minutes playing before work. Drums, hats, bass, lead, pad, arp – build ’em up, break ’em down, crank it, back off – the sound stayed nice and full and clean. Yes! This is exactly what I wanted.