What is the difference between a flanger and a chorus?

The length of the delay. A chorus delays the copy by about fifteen milliseconds so it is heard as a second voice; a flanger delays it by a millisecond or two, so it interferes with the original and becomes a comb filter. The feedback control then makes the flanger resonant, which a chorus does not need.

Why does high feedback sound like a howl?

Because feedback reinforces each tooth of the comb repeatedly, so the resonance grows sharper and more sustained. Past about eighty percent the effect stops sounding like a filter and starts behaving like a resonating body of its own, which is why the control stops below the point of self-oscillation.

Why can I not set a very fast sweep?

Because the rate range is chosen for the effect's musical use. Very fast modulation of a short delay turns into a vibrato-like pitch wobble rather than a sweep, and the depth control already reaches far enough to make the effect obvious at a slow rate.

Does the flanger work on a mono file?

Yes, since the operation is on the signal itself rather than on the difference between channels. It is often more dramatic on stereo material only because the sweep is heard against a wider image, not because the effect requires two channels.

How is the comb spacing determined?

By the delay length. Notches appear at frequencies whose half-wavelength matches the delay, so a one millisecond delay spaces them about five hundred hertz apart, and the spacing grows as the sweep shortens the delay. That even spacing is what distinguishes the flanger from the phaser.

Flanger Effect

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Flanger Effect sweeps a short delay against the original and feeds the result back, which produces a comb of resonant peaks that slides up and down. It is the jet-plane whoosh rather than the chorus's doubling.

What is Flanger Effect?

Choose a file, set the sweep rate, depth, feedback and mix, and apply; the report gives the settings and notes any limiting.

The controls:

A rate from a twentieth of a hertz to five, defaulting to a third of a hertz, which is a slow sweep.
A depth from nothing to five milliseconds, defaulting to two, so the delay moves within a very short range.
A feedback from nothing to ninety percent, defaulting to sixty.
A mix from nothing to everything, defaulting to seventy percent.
A fixed one millisecond base delay, which together with the depth is what makes this a flanger rather than a chorus.

The difference between this and a chorus is almost entirely one of scale, and the consequence is large. With a delay of a millisecond or two, the copy and the original interfere across the whole audible band, producing a comb of evenly spaced peaks and notches that moves as the delay changes; because the spacing is harmonic, the ear hears the sweep as a single resonating tone climbing and falling, which is the effect's whole character. The feedback is what makes it resonant rather than merely hollow: the delayed signal is fed back into the delay, so each tooth of the comb is reinforced repeatedly, and the impulse response settles into amplitudes that fall by the feedback factor at each multiple of the delay. That is why high feedback with a slow sweep produces the classic jet whoosh, and why the panel keeps the control below the point where the comb would begin to sustain on its own. The sweep rate decides whether the effect is heard as movement or as a static colour: a very slow rate makes the material sound as though it is passing through a fixed resonance, while a faster one is unmistakably a sweep. Depth sets how far the teeth travel, and a larger depth moves the peaks further apart as the sweep runs. The mix brings the processed signal forward against the dry one, and at nothing the dry passes through exactly.

Where it stops:

No independent control of the sweep shape.
Feedback is capped below the point of self-oscillation.
No stereo offset between the channels, so both sides sweep together.
No tempo synchronisation, so the rate has to be set against the music by ear.
The base delay is fixed rather than exposed.
Output is sixteen bit WAV.

Use it on guitars, synth pads, drum loops or anything that benefits from movement: the effect is at its best when the sweep is slow enough to be felt rather than noticed. When the goal is doubling a single part rather than colouring it, the chorus uses a longer delay to produce a second voice instead, and when the notches need to be unevenly spaced rather than harmonic, the phaser is the tool that produces them. The effect is at its most convincing when the sweep is slow enough to sit under the music rather than on top of it, which is why rates below one hertz are the useful half of the range.

How to use Flanger Effect

Drop an audio file onto the panel.
Set a slow rate and a small depth to hear the character before pushing either.
Raise the feedback for resonance, remembering that past eighty percent the comb begins to howl.
Set the mix and apply, then check the report for limiting.

When to use Flanger Effect vs related tools

Flanger Effect is the tool for a moving resonance, which suits clean guitars, synth pads and anything that wants a whoosh. Chorus Effect uses a longer delay to produce doubling rather than filtering, and Phaser Effect sweeps allpass notches that are unevenly spaced. When the effect is applied rhythmically, Echo Delay Generator with a slow rate can be timed against the music, and Stereo Widener changes the width without adding movement.

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