Why does a chorus use a fifteen millisecond delay?

Because that is the region where the copy is heard as a separate voice rather than as a filter. Shorter delays let the copy interfere with the original and produce comb filtering, which is the flanger's territory; longer ones separate into a distinct echo. Fifteen milliseconds sits in the narrow band between them.

What happens if the depth is very high?

The pitch of the copy moves further as it is swept, because changing the length of a delay line changes the pitch of what it outputs. That is heard as an obvious wobble rather than as doubling, which is why the depth control tops out at a modest figure.

Why do both channels move together?

Because independent modulation would move the two sides apart and smear the stereo image. A coherent oscillator keeps the image where it was while still adding movement, which is the effect a chorus is supposed to produce on a mix rather than a spread.

Why might the output be limited?

Because the dry signal and its copy are summed, and on already-loud material the sum can pass full scale. The report tells you when that happened. Lowering the mix reduces the risk, since less of the copy is being added to the original.

Does a zero mix change anything at all?

No. At zero the dry signal is passed through exactly, which makes it a useful way to confirm that the processing is behaving as expected. It also means the effect can be dialled in gradually from a known-clean starting point.

Chorus Effect

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Chorus Effect thickens a sound by mixing it with a slightly delayed, gently swept copy of itself. The result sits close enough to the original to fuse with it and far enough away to sound like a second performance.

What is Chorus Effect?

Choose a file, set the sweep rate, depth and mix, and apply; the report confirms the settings and warns if the output had to be limited.

The controls:

A rate from a tenth of a hertz to eight, defaulting to one and a half, which is the speed of the sweep.
A depth from nothing to twelve milliseconds, defaulting to five, which is how far the delay moves either side of its resting point.
A mix from nothing to everything, defaulting to fifty percent, which is the balance between the dry signal and the swept copy.
A fixed fifteen millisecond base delay that is not exposed, because it is the value that makes a chorus sound like doubling rather than like a flange.

The mechanism is a delay line whose length is modulated by a low frequency oscillator, and a few details decide whether the result is usable. The base delay sets the character: around fifteen milliseconds the copy is heard as a second voice, while delays of a few milliseconds or less produce the comb-filtered sweep of a flanger instead. The depth is the amount of movement, and it is deliberately small, since a large sweep turns a doubling effect into an obvious wobble. The oscillator's phase is coherent across the channels, which means both sides move together rather than independently; that keeps the stereo image stable, whereas independent modulation would smear the image and make the effect sound wide but unfocused. The mix balances the two signals, and at nothing the dry signal passes through exactly, so a zero mix is a genuine bypass rather than an approximation. Because the two signals are added rather than blended in turn, the summed peak can exceed full scale on material that is already loud, and the report says so when the output had to be limited. That limiting only occurs when the sum would have clipped, so it is a safety measure rather than part of the effect.

What it does not do:

No independent modulation per channel, which is deliberate.
No additional voices, so the result is two-part doubling rather than a full ensemble.
No filter or tone control on the copied signal.
The base delay is fixed rather than adjustable.
No control over the oscillator's shape.
Output is sixteen bit WAV.

Use it to make a single-tracked vocal sound like two takes, to thicken a synth pad, or to add movement to a clean guitar part. When the delay should be short enough to comb rather than to double, the flanger and the phaser produce that sweep, and when the aim is to widen an existing stereo image rather than to add a copy, the stereo widener does that without adding a signal. A chorus works best on a single voice or a single instrument rather than on a full mix, since every element it touches acquires the same movement, and a part that is already thick can end up sounding indistinct once a second copy is added to it.

How to use Chorus Effect

Drop an audio file onto the panel and let it decode.
Set the rate for how fast the copy should move and the depth for how far.
Set the mix to balance the copy against the dry sound.
Apply the chorus, listen for any limiting in the report, and download the WAV.

When to use Chorus Effect vs related tools

Chorus Effect is the tool for thickening one part into two, which is why it sits behind most doubled vocals and chorused guitars. Flanger Effect and Phaser Effect use much shorter delays, or none at all, to sweep the frequency response instead. To make an existing stereo image wider without adding a copy, Stereo Widener is the direct tool, and Echo Delay Generator produces repeats long enough to be heard as separate events.

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