A limiter is an extreme compressor. Where a compressor reduces levels above a threshold by a set ratio (say, 4:1 or 8:1), a limiter uses an effectively infinite ratio — meaning once the signal hits the threshold, it simply refuses to let it go higher. The threshold becomes a hard ceiling.
Limiter vs. compressor
The difference is in the ratio and intent. A compressor is a dynamics shaping tool — it controls the relationship between loud and quiet moments to add punch, glue, or consistency. A limiter is a protection circuit — its job is to stop the signal from ever exceeding a level that would cause damage or distortion. In practice, limiters often have very fast attack times (catching peaks instantly) and release times tuned so the limiting is as transparent as possible.
Where DJs encounter limiters
- The mixer master output. Most professional DJ mixers have a built-in limiter on the master bus. It's there to protect the downstream signal chain — and the speakers — from a sudden gain spike.
- DJ software. Rekordbox, Serato, Traktor, and others include a limiter on the master output. It's usually on by default and often invisible — which can give a false sense of security about gain staging.
- Venue PA systems. Almost every professional PA system has limiting at some point in the chain — in the amp rack, in the processing, or both. The venue engineer sets it to protect the speakers. You don't control it, and you shouldn't assume it's doing your job for you.
The limiter is not a substitute for gain staging
If your signal is consistently hitting a limiter hard enough to trigger it, the audio is already distorting before the limiter catches it — the limiter is catching the aftermath, not preventing the problem. Think of it as a seatbelt: absolutely good to have, not a reason to drive recklessly. Proper gain staging keeps you out of the limiter's territory in the first place.
The tell-tale sign of a limiter working too hard is a loss of dynamics — the music starts to feel squashed and flat, like the peaks and the quiet moments are all the same level. That's the limiter constantly clamping down because the average level is too high. Back off the gain, and the music breathes again.