Compressor vs Limiter: What's the Difference and When to Use Each

A compressor turns down a signal by a set ratio (for example 4:1) once it passes a threshold, so it controls and shapes dynamics. A limiter is an extreme compressor, with a very high ratio and a very fast attack, that stops the signal from ever going above a ceiling, which is why it usually sits last on the master.

So the compressor vs limiter (or limiter vs compressor) question isn't really either-or. They're the same idea set to different jobs. The compressor is a shaping tool you use all over a mix. The limiter is a safety and loudness tool you use in a few specific places.

How does a compressor work?

A compressor watches the level of the incoming signal. When it crosses the threshold, the compressor reduces the gain according to the ratio. At 4:1, a signal that goes 8 dB over the threshold comes out only 2 dB over. Quiet parts below the threshold pass through untouched.

• Threshold: the level where compression starts.
• Ratio: how hard it compresses above the threshold. 2:1 is gentle, 4:1 is firm, 8:1 is heavy.
• Attack: how quickly it clamps down once the signal crosses the threshold. A slower attack lets the transient through, which keeps drums punchy.
• Release: how quickly it lets go once the signal falls back.
• Knee: whether compression starts abruptly (hard knee) or eases in around the threshold (soft knee).
• Makeup gain: turns the whole signal back up after compression, so you compare at a matched level.

Because attack and release are adjustable, a compressor changes the shape of a sound, not just its level. A slow attack with a fast release makes a snare snap. A fast attack with a slow release flattens a vocal into a steady, upfront line.

What is a limiter in audio?

A limiter sets a ceiling and does whatever it takes to keep the signal below it. The ratio is fixed so high it's effectively infinite, and the attack is nearly instant. A brickwall limiter guarantees nothing gets through above the ceiling.

Most limiters have just a few controls: an input gain or threshold that drives the signal into the limiter, a ceiling or output level, and a release. Better ones add lookahead, which delays the audio slightly so the limiter can see a peak coming and turn down smoothly instead of chopping it. Many also offer true peak detection, which catches peaks that only appear between samples once the audio is converted or encoded.

Push the input gain up and the limiter holds the ceiling while the average level rises. That's how a mastering limiter makes a track louder. Push too far and you'll hear it: pumping, flattened transients and a dull, crowded sound.

Compressor vs limiter: side by side

When to use a compressor

• Vocals. Evening out the level so quiet words don't disappear and loud ones don't jump out. Most vocal chains have at least one compressor; see our vocal EQ guide for what comes around it.
• Drums. A slower attack lets the stick hit through while the compressor tucks in the ring, which makes kicks and snares punchier.
• Bass. Steadier notes make the low end feel solid and sit at one level against the kick.
• Bus glue. A low ratio (1.5:1 or 2:1) with 1 to 2 dB of gain reduction on a drum or mix bus makes parts feel like they're moving together.
• Sidechain ducking. A compressor keyed from the kick pulls the bass or pads down on every hit. Our sidechain guide covers the setup in every major DAW.
• Parallel compression. Blend a heavily compressed copy under the dry signal to add density without losing transients.

When to use a limiter

• On the master, last in the chain, to raise loudness and make sure the output never clips.
• On a single track with occasional spikes, like a percussive synth or a shouted ad-lib, where you want to shave a few peaks without changing the tone.
• After a compressor on vocals, as a safety net for the loudest moments.
• On live input or streams, where a sudden peak would otherwise clip the recording or broadcast.

On a master you plan to release yourself, many engineers set the limiter ceiling around -1 dBTP so that lossy encoding doesn't push peaks into clipping. If the limiter is reducing more than a few dB all the time, the mix usually needs fixing earlier in the chain rather than more limiting.

Can you use a compressor as a limiter?

Partly. Turn the ratio to its maximum, set the attack as fast as it goes and a compressor will behave much like a limiter. What it may not have is lookahead and true peak detection, so very fast peaks can still slip past. For catching the odd peak on a track that's fine. For the final stage of a master, use a real limiter.

The reverse doesn't work well. A limiter has no ratio or attack to shape with, so using it to control a vocal or a drum loop just flattens it.

Types of compressor, briefly

Compressors are often described by the circuit designs they come from, and each has a recognizable feel. Plugin emulations borrow the same names.

• FET: very fast and aggressive, with lots of attitude. The 1176 is the famous example, and it's a staple on vocals and drums.
• Optical: smooth and program-dependent, with a release that changes with the material. The LA-2A is the classic, loved on vocals and bass.
• VCA: clean and precise. Common on drum and mix buses.
• Variable-mu: tube-based and gentle, often used for soft glue on a mix or master.

If you'd rather not juggle threshold, ratio and attack on every vocal, Velvet, our vocal chain plugin, puts a compressor behind a single Compress knob, placed after the low cut and de-esser and before the EQ, in the order a vocal chain usually runs.