Wow and flutter are small, unsteady pitch fluctuations you hear on tape and vinyl, caused by tiny variations in the speed of the machine as it records or plays back. Wow is the slow drift, flutter is the faster wobble, and together they give old recordings that gently unstable feel.
This is about what wow and flutter are and where they come from, on any tool, in any DAW. It is a pitch effect from speed instability, which is a different thing from the tone colouring of tape saturation.
Wow and flutter are small, unsteady pitch fluctuations you hear on tape and vinyl, caused by tiny variations in the speed at which the medium moves. A tape machine or a turntable is supposed to run at one steady speed, but in practice the speed drifts a little, and when the speed changes the pitch changes with it. Your ear hears those tiny speed wobbles as the note wavering slightly up and down. That is all wow and flutter is: speed that is not perfectly constant, heard as pitch that is not perfectly steady.
It is worth being clear about what kind of effect this is. Wow and flutter is a pitch effect, a movement in pitch caused by unsteady speed. That makes it a different thing from tape saturation, which is a tone effect: added harmonics and a gentle compression that colour the sound without moving its pitch. Both come from tape and both are part of the tape sound, but they are not the same ingredient. One wobbles the pitch, the other warms the tone.
Speed instability heard as pitch instability. If the note is drifting or shimmering slightly out of tune in an organic way, that is wow and flutter. If the sound is warmer and thicker but sitting in tune, that is saturation, a separate effect.
The difference is speed: wow is the slow pitch drift, and flutter is the faster pitch wobble. They are the same underlying fault, unsteady speed heard as unsteady pitch, split by how quickly the wobble happens. Wow is a slow, wavering, seasick warble at a low rate, roughly under about four times a second. Flutter is a faster shimmering, fluttering unsteadiness at a higher rate. As a rough guide, wow you tend to notice as the pitch moving, and flutter you tend to feel as a texture or graininess more than as an obvious change in pitch.
| Rate | Sounds like | Most obvious on | |
|---|---|---|---|
| Wow | Slow, roughly under about four times a second | A wavering, seasick warble, the pitch drifting up and down | Held notes, piano, sustained pads and vocals |
| Flutter | Faster, a higher rate than wow | A shimmering, fluttering unsteadiness, more texture than melody | The general grain of the sound rather than one note |
In practice the two usually happen together and blur into one another, which is why they are almost always named as a pair. The slow drift of wow gives a recording its swimming, unstable quality, while the faster shimmer of flutter adds a fine graininess on top. For a fuller walk through how these sit alongside the other parts of the tape sound, the wow, flutter and saturation guide goes into the numbers and how much reads as broken.
Wow and flutter are caused by anything that stops the medium moving at a perfectly constant speed. On a tape machine or a turntable the sound is written and read at a fixed speed, so any small change in that speed shows up as a change in pitch. A few common causes account for most of it:
The slower causes tend to produce wow and the faster ones tend to produce flutter, but they overlap, and a tired machine usually has some of both. The healthier and better maintained the machine, the less wow and flutter it has, which is why a well kept professional deck is nearly steady while a cheap or worn one wanders audibly.
Producers add wow and flutter on purpose because the same instability that hi-fi engineers worked hard to remove is exactly what makes a sound feel vintage and hand made. In hi-fi gear, wow and flutter is treated as a fault, a sign the machine is not holding pitch the way it should, and better decks are prized for having as little of it as possible. In lo-fi, vintage and tape styles it is the opposite: that faint, unstable, wandering quality reads as nostalgic warmth, the sound of a real, imperfect machine rather than a perfectly clean computer. What is a defect in one context is character in the other.
You do not need an old tape machine to get it now. The usual route is a tape emulation plugin that models wow and flutter so you can dial in as much drift and wobble as you want, and another route is a tape based instrument that has this movement built into how it behaves as you play. A little goes a long way, and it tends to sit best under sustained sounds where the pitch has room to drift, rather than under a clean lead or vocal where the ear knows exactly what pitch it should be. Remember too that wow and flutter is only the pitch movement; the warmth people also associate with tape comes largely from saturation, which is a separate, tone based effect you often reach for alongside it.
Everything above works by hand on any tape plugin that has wow and flutter controls. The quickest way to understand what it does, though, is to run a sound through modelled tape and listen to the pitch start to move.
SILT is a generative tape-loop instrument that runs your sound through modelled tape, so it adds exactly this wow and flutter as you play, along with saturation, dust and dropout. It models the behaviour of tape rather than being real tape, but that is enough to hear the pitch drift and the gentle worn quality on your own sound in a few seconds. If you would rather feel what wow and flutter does than read about it, this is a quick way in. It runs in your browser, or as a plugin on your own tracks, an Audio Unit, a VST3, an AAX and a standalone app.
Free to hear in the browser, no signup. Everything above still works by hand on any tape plugin with wow and flutter controls, which is rather the point of writing it down.
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