Chorus is a modulation effect that makes a single sound feel like several of the same sound playing at once, the way a choir is fuller than one voice. It works by adding a copy of the sound that is slightly late and slightly out of tune, and keeping that copy gently moving. The result is thicker, wider and softly shimmering, without a single note being changed.
The controls are much the same on almost every chorus, hardware or plugin: a rate, a depth, a mix or blend, and sometimes a voices count. None of this is tied to one product.
Chorus is a modulation effect that makes one sound feel like several of the same sound playing together. When a group of people sing the same note, or a string section plays one line, no two of them are ever perfectly in tune or perfectly in time. Those tiny differences in pitch and timing are a large part of what makes a choir or a section sound so full and alive. Chorus recreates that from a single source by adding a slightly delayed, slightly detuned copy of the sound and keeping it gently moving underneath the original.
What you hear is a sound that seems thicker, richer and wider than the one you fed in, often with a soft shimmer to it. The dry part stays recognisable, but it now sits inside a small cloud of itself rather than standing alone. Used lightly it simply adds body and width; pushed harder it becomes an obvious, watery wobble that is a strong character in its own right.
Chorus does not add new notes or harmony. It is still one part, played once, with a wavering copy of itself mixed in beside it. Everything it is known for, the thickness, the shimmer and the width, comes from that copy being slightly late and slightly out of tune and never sitting still. Turn the effect off and the extra voices vanish, because there was only ever the one.
A chorus takes a copy of the signal, delays it by a short amount, usually around 10 to 40 ms, and uses a slow low-frequency oscillator, or LFO, to move that delay time up and down. Stretching and squeezing a delay like that also stretches and squeezes the copy, so its pitch wavers slightly above and below the original as the delay lengthens and shortens. That detuned, drifting copy is then mixed back in with the dry signal, and the two together sound thicker and wider than the dry signal on its own.
The short delay is the key. At only a few tens of milliseconds it is too brief to hear as a distinct echo, so instead of a repeat you hear one blended sound. The constant, gentle detuning from the LFO is what stops the copy from lining up exactly with the original, which is why the result shimmers and moves rather than sitting still. Add more than one moving copy and the effect gets lusher, closer to a whole section than a pair.
Chorus sits next to a couple of related effects that work the same way. A flanger uses a much shorter delay that it sweeps up and down, and that shorter delay creates a bank of moving notches in the tone, so instead of a gentle waver you get a strong, hollow, sweeping whoosh, the sound often described as a jet flying over. Doubling is the plainer relative: a fixed short delay with little or no pitch movement, which sounds less like a shimmer and more like the part was simply recorded twice. Chorus sits between the two, close enough to a flanger that many units offer both.
The main controls set how fast the copy wobbles, how far it drifts, and how much of it you hear: rate, depth, a mix or blend, and on some units a voices count. The labels vary from one chorus to another, but they nearly always come down to those few. Here is what each one does and a sensible place to start.
| Control | What it does | A place to start |
|---|---|---|
| Rate / speed | How fast the LFO moves the delay up and down. Slow is a gentle drift, fast is an obvious wobble that can turn seasick. | Slow, a gentle drift for most parts |
| Depth / amount | How far the delay time swings, which sets how much the pitch wavers. More depth is a stronger, more detuned effect. | Low to moderate; a little goes a long way |
| Mix / blend | The balance of dry sound to the wet, chorused copy. Keeping some dry keeps the part clear. | Well below fully wet, then add to taste |
| Voices | How many delayed copies are added. More voices is lusher and wider, closer to a section than a double. | One or two for subtlety, more for a wash |
| Delay / centre | The base delay the LFO moves around, when a unit exposes it. Shorter is tighter, longer is more spacious. | Leave at the default unless you want a certain sound |
Rate and depth are the two you will reach for most, and they interact: a slow rate with a lot of depth gives a wide, lazy drift, while a fast rate with a little depth gives a tighter flutter. It is easy to overdo both, and a chorus that calls attention to itself on every part usually has one or the other set too high. The mix control is the safety valve, since it decides how much of all that movement actually reaches the output, and it behaves like the blend on any other effect. There is a whole guide on dry versus wet signal if you want the fuller picture on that one control.
Chorus is good for thickening and widening sounds that feel thin, static or too centred: pads, guitars, synths and backing vocals, and turning a narrow, mono part into something that spreads across the stereo field. It is a texture and width effect, so it earns its place where you want a part to feel bigger and more alive without changing a single note.
Go easy with chorus on bass and other very low parts. The effect works by detuning and smearing whatever you feed it, and on the deep low end that wavering pitch tends to make the bottom of a mix feel loose, wide and unfocused, exactly where you usually want it solid and centred. Many people keep chorus off the lowest parts altogether, or apply it only to the higher content of a sound, so the top can shimmer while the low end stays firm.
Chorus is a finishing move. It makes a part wider, thicker and more alive, but it cannot invent the part in the first place, and a dull idea in a lush chorus is still a dull idea. The interesting work is writing something worth widening, and the effect is easiest to judge once the raw part already stands up on its own.
We do not make a chorus plugin, and this guide is not a pitch for one. But chorus is easiest to use well when the sound going into it already moves and sits wide on its own, so you reach for it to taste rather than to fix a flat, lifeless part. That is what our instruments are built to do. The Collection is our three instruments together, ARGISH, SILT and REHEAT, with three separate licence keys. Each one already carries its own width and movement: ARGISH is a self-playing drone synth, SILT is a tape-loop instrument that wears sounds into texture, and REHEAT writes acid lines. Parts like that arrive with life of their own, so chorus becomes a choice rather than a rescue.
Every one ships as AU, VST3, AAX and a standalone app on macOS, signed and notarized, and a VST3 on Windows. You can hear one free in your browser first, no install and no account, then decide.
Everything on this page works by hand with any chorus in any DAW, which is rather the point of writing it down.
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