Unison is a synth mode that stacks several copies of the same note and detunes them very slightly, so they beat against each other and blend into one thick, wide, shimmering sound. It is how a single thin oscillator becomes a big, rich pad or a huge lead. Turn it up too far and the same trick smears into something washy and out of tune, so the skill is in how much you use.
The idea applies to any synth or plugin, in any DAW or a browser instrument. Unison and detune mean the same thing wherever you meet them. None of this is tied to one product.
Unison is a synth setting that plays several copies of the same note at once, each from the same oscillator, and detunes them very slightly against each other. On its own one oscillator makes a fairly pure, thin tone. Stack a handful of copies that are all a touch sharp or flat of one another and the tiny differences make them beat and shimmer, so the ear hears the whole pile as one fat, wide sound instead of separate notes.
Each copy is usually called a voice. The oscillator is the part that makes the raw tone, and unison simply runs several of it in parallel, spreads their tuning a little, and often pans them across the stereo field. The more voices you add and the more you detune them, the thicker and wider the result, up to a point.
Unison stacks copies of the same note, not different notes, so it thickens a single pitch rather than adding harmony. It can sound a little like a chorus effect, and for good reason, since both work by detuning copies of a signal, but unison is built into the synth voice itself rather than added on afterwards.
The unison controls set how many copies you stack, how far apart they are tuned, and how wide they sit. Four turn up on almost every synth, though the names vary. Here is what each one does.
| Control | What it does | Rule of thumb |
|---|---|---|
| Voices (unison count) | How many copies of the note are stacked. More voices give a thicker, denser sound. | Two or three for subtle warmth, five to seven for a wide lead |
| Detune | How far apart the copies are tuned. A little makes them shimmer; a lot makes them wash out and drift out of tune. | Keep it gentle, and back off if the pitch starts to feel unstable |
| Stereo spread (width) | Fans the copies across the left and right of the stereo field for a wider image. | Wide for pads and leads, narrow or off for bass |
| Phase or blend | Sets where the copies start, or mixes the plain centre note against the detuned ones. | Leave at the default until you know a patch well |
Start with the voice count and detune, since those two do most of the work, and treat spread and blend as finishing touches. A good way to learn them is to hold one note, turn the detune up slowly until it shimmers without sounding sour, then set the width to taste.
A supersaw is a sawtooth wave run through heavy unison: several detuned sawtooth copies stacked into one broad, shimmering tone. It is the classic wide synth lead, the huge, bright sound behind a great deal of trance, dance and pop, and it is really just unison and detune pushed for effect on the richest raw waveform there is.
Many synths offer it as a ready-made waveform so you do not have to build the stack yourself, but under the name it is the same trick this guide describes: copies of one sawtooth, slightly detuned and spread. If you want to shape one into a part, our guide on how to make a lead sound takes it further. A little goes a long way, and even a supersaw usually sits better in a mix with the detune lower than you first expect.
Unison sounds great but it is not free, and the same things that make it wide can work against you. There are three tradeoffs worth keeping in mind.
Reach for unison when a sound is too thin or too narrow, not by default. Two or three lightly detuned voices already add real warmth, and you can always add more. Many patches that feel harsh or muddy are simply carrying more unison, and more detune, than the part actually needs.
Unison and detune click into place far faster when you can hear a thin note turn wide while a sound is playing. Reading the theory gets you the map; hearing it is what makes it stick.
ARGISH is a self-playing synthesizer. Its pads and leads have the width and shimmer this guide is about, and because it plays itself you can hear that thickness in a real part rather than only read about it. Set a mood and a key, build a progression on the chord wheel, and it composes and evolves in the background while you turn knobs and hear what they change. It runs in your browser, or as a plugin in your DAW: an Audio Unit, a VST3, an AAX for Pro Tools and a standalone app.
You can hear it free in your browser first, no install and no account, then decide.
Everything on this page also works by hand on almost any synth with a unison mode, which is rather the point of writing it down.
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