A flanger mixes a sound with a copy of itself that is delayed by a very short, constantly moving amount, roughly 1 to 10 ms. That short delay stacks the copy against the original to form a comb filter, a row of evenly spaced notches in the tone, and sweeping the delay slides those notches up and down. The result is the familiar whooshing, jet-plane sweep.
The controls are much the same on almost every flanger, hardware or plugin: a rate, a depth, a feedback or regeneration, and a mix. None of this is tied to one product.
A flanger is a modulation effect that mixes a copy of a sound with the original after delaying that copy by a very short, constantly sweeping amount, usually somewhere around 1 to 10 ms. On its own a delay that short is far too brief to hear as an echo. Instead, stacking the delayed copy against the original reinforces some frequencies and cancels others at the same time, and moving the delay makes that pattern slide, which is what produces the strong, hollow, whooshing sweep a flanger is known for.
The sound is often described as a jet plane passing overhead. The name comes from an old tape trick: playing the same recording on two machines and pressing a finger on the flange of one reel to slow it a hair, so the two copies drift a tiny distance apart and back. A modern flanger does the same thing electronically, with far more control. Used gently it adds a subtle sense of motion; pushed hard, with plenty of feedback, it becomes a metallic, resonant sweep that is a strong character in its own right.
A flanger does not add new notes or harmony. It is still one part, played once, with a very short, moving copy of itself mixed in beside it. Everything it is known for, the whoosh, the metallic ring and the sense of motion, comes from that copy being delayed by a tiny, sweeping amount so the two versions comb-filter against each other. Turn the effect off and the sweep vanishes, because there was only ever the one sound.
A flanger works by mixing the dry sound with a copy delayed by a very short amount and sweeping that delay up and down with a low-frequency oscillator, or LFO. When you add a signal to a slightly delayed version of itself, some frequencies line up and get louder while others arrive out of step and cancel, which carves a row of evenly spaced dips, or notches, across the tone. That pattern of peaks and notches is called a comb filter, because on a graph it looks like the teeth of a comb.
The short delay sets where those notches sit, and sweeping the delay with the LFO slides the whole comb up and down the frequency range. That moving set of notches is the whoosh you hear. Because the delay is so short, roughly 1 to 10 ms, the notches are spaced far apart and there are only a handful of them, which is why a flanger sounds hollow and resonant rather than gentle. A flanger is really a very short, swept version of a plain delay effect, so if the idea of delaying a copy of a sound is new, our guide on the delay effect covers the basics.
The two controls you reach for first are rate and depth. Rate, sometimes called speed, sets how fast the LFO sweeps the delay, from a slow drift that takes several seconds to a fast, dizzy wobble. Depth sets how far the delay swings, which is how far the notches travel across the tone, so more depth is a wider, more dramatic sweep. Between them they shape the whole motion of the effect.
Two more controls decide how strong it is. Feedback, sometimes labelled regeneration or resonance, sends some of the delayed copy back through the delay again, which deepens the notches and makes them ring; it intensifies the effect and, pushed far enough, can whistle or scream on its own. A mix or blend then sets the balance of dry sound to the swept copy, and keeping some dry keeps the part clear and the sweep sitting under it rather than swallowing it.
The difference comes down to the length of the delay and how the notches are made. A flanger uses a very short delay, roughly 1 to 10 ms, swept by an LFO, which makes evenly spaced comb-filter notches that move and give the hollow whoosh. A chorus uses a longer delay, around 10 to 40 ms, wavered rather than swept, so instead of a whoosh you get a thicker, wider, gently detuned sound. A phaser makes its notches a different way entirely, with a bank of all-pass filters instead of a delay, so its notches are not evenly spaced and its sweep is smoother and less metallic.
| Effect | How it works | What you hear |
|---|---|---|
| Flanger | A very short delay, roughly 1 to 10 ms, swept by an LFO and often fed back, making evenly spaced comb-filter notches that move. | A strong, hollow, whooshing sweep, the classic jet-plane sound, metallic when the feedback is high. |
| Chorus | A longer delay, around 10 to 40 ms, wavered by an LFO so the copy drifts slightly out of tune rather than sweeping. | A thicker, wider, gently shimmering version of the sound, with no whoosh. |
| Phaser | A bank of all-pass filters instead of a delay, swept by an LFO, so the notches are not evenly spaced. | A softer, hollow sweep that is smoother and less metallic than a flanger. |
In practice the three sit on a scale from gentle to dramatic. A chorus is the softest, thickening a sound without calling much attention to itself; our guide on the chorus effect covers it in full. A flanger is the most aggressive, with its deep, moving notches and metallic ring. A phaser sits between them, a hollow sweep that is smoother than a flanger because its notches are spread unevenly rather than stacked in a regular comb. Many units offer more than one of the three, since they are close cousins built from the same idea of a moving copy.
A flanger is good for adding movement to a sound that would otherwise sit still: a slow sweep over drums, guitars, synths or a whole bus that makes the part feel like it is breathing, and a rising sweep that builds tension into a chorus or a drop. It is a motion and character effect, so it earns its place where you want a sense of movement rather than a change to the notes.
A flanger is a strong, obvious effect, so a little often goes a long way. Deep, fast flanging with high feedback grabs attention and can quickly feel dated or seasick if it runs through a whole song. Many people automate it in for a moment, a build, a single bar or a breakdown, then take it back out, so it stays a special effect rather than a constant one. When you do want it as a steady texture, back the depth and feedback off until it reads as gentle motion rather than a whoosh.
A flanger is a finishing touch. It adds movement and character to a sound, but it cannot invent the sound in the first place, and a flat, static part with a flanger swept across it is still a flat, static part underneath. The interesting work is making a source that already moves, so the flanger becomes a flourish you add by choice rather than a way to fake life that is not there.
We do not make a flanger plugin, and this guide is not a pitch for one. But a flanger is easiest to use well when the sound going into it already moves and evolves on its own, so you sweep it in as a flourish rather than to inject life into a static 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 motion: 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 movement of their own, so a flanger 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 flanger in any DAW, which is rather the point of writing it down.
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