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Compressors, Gates and Limiters Explained
Three processors that every digital mixer includes and most people leave switched off. What each does, and the settings that are actually useful live.
~8 min read · Updated August 2026 · By the Stage Supply team
In this guide:The three · The controls · Live uses · Feedback · Picks · FAQ
Every digital mixer sold today includes a compressor and a gate on every channel, and a limiter on the outputs. They came free with the desk, which is roughly the value most people extract from them.
All three are automatic level controls. They differ in what they do and when they act, and once that is clear the controls stop being mysterious.
What each one does
- A **compressor** reduces the level of anything above a threshold, making loud parts quieter so the whole signal sits in a narrower range. That lets you raise the average level without the peaks getting away.
- A **gate** does the opposite at the bottom. It mutes, or reduces, anything below a threshold, so a microphone is only open when something is actually happening in front of it.
- A **limiter** is a compressor with a very high ratio and a fast attack, used as a ceiling. Nothing gets past it. Its job is protection rather than tone.
The five controls, in plain terms
| Control | What it sets | Practical effect |
|---|---|---|
| Threshold | The level at which the processor starts working | Lower threshold means more of the signal is affected |
| Ratio | How hard it acts above the threshold | 2:1 is gentle, 4:1 is firm, 10:1 and above is limiting |
| Attack | How quickly it responds | Fast attack catches transients, slow attack lets them through |
| Release | How quickly it stops | Too fast sounds pumping, too slow chokes the next phrase |
| Makeup gain | Level added after processing | Restores the level the compression removed |
The most common beginner error is a low threshold and a high ratio, which flattens everything, followed by a lot of makeup gain, which brings up the noise and gets closer to feedback.
Where they earn their keep live
Vocals
A compressor on a vocal is the most useful one on the desk. A singer who whispers a verse and belts a chorus is 20 dB apart, and no fader ride keeps up. A modest ratio around 3:1 with the threshold set so the loud passages show a few dB of reduction evens it out without sounding processed.
Drums
Gates on the close microphones stop the snare mic hearing the whole kit, which tightens the sound. They also need care, because a gate that closes too fast cuts the tail off the drum and a gate set too high loses the quiet hits. See how to mic a drum kit.
Bass and acoustic instruments
Compression keeps a bass sitting still in the mix rather than lurching. On acoustic guitar with a pickup it tames the peak when someone digs in.
Main output
A limiter across the main output is protection for the loudspeakers and the audience, not a mix tool. Set it as a ceiling that is only reached on the loudest moment, and leave it alone.
One thing at a time
Add one processor, listen with it in and out, and keep it only if it improved something. A channel with a compressor, a gate and four bands of EQ, all set by habit, is usually worse than the same channel left alone.
Compression and feedback
Compression makes feedback more likely, not less, and it is worth understanding why. A compressor raises the average level relative to the peaks, which is exactly the condition that gets a system closer to ringing. Heavy compression on a vocal in a live room is a common cause of a system that feeds back at a level it used to be fine at.
If a channel is fighting feedback, fix the gain structure and the position first. See how to stop feedback and gain staging.
Popular picks from the shop
Frequently asked questions
What is a good compressor setting for live vocals?
A starting point is a ratio around 3:1, a medium attack, a medium release, and the threshold set so that the loudest passages show a few decibels of gain reduction and quiet passages show none. Adjust by ear from there.
What is the difference between a compressor and a limiter?
Only degree. A limiter is a compressor with a very high ratio and a fast attack, used as a hard ceiling rather than as a tone or dynamics tool.
Should I gate everything?
No. Gates suit close-miked drums and occasionally a loud stage vocal. On most channels a gate causes more problems than it solves, particularly on anything with a natural decay.
Where does the limiter go?
On the main outputs, and on in-ear monitor feeds where it is genuinely a safety device. Set it as a ceiling and leave it.
