Why does a warble find faults that a steady tone does not?

Because it visits every frequency between the centre minus the deviation and the centre plus the deviation, over and over. A resonance, a loose panel or a driver fault only misbehaves when the tone reaches it, so a moving signal gives the fault a chance to announce itself while a fixed tone either lands on it or misses it entirely.

What modulation rate should I choose?

Two hertz is the traditional starting point: fast enough that the sweep is clearly moving and slow enough to follow by ear. Raise it toward ten or above and the sound turns ragged, which is useful for spotting a rattle but makes the pitch hard to track. Slower than one hertz and the movement becomes a long glide.

How wide should the deviation be?

Wide enough to cover the band of interest, and no wider than the system can comfortably reproduce. With a centre of a thousand hertz, a deviation of four hundred exercises eight hundred to fourteen hundred, while the maximum of five thousand sends the tone almost to zero at the bottom and past the audible top at the top.

Does the level change as the pitch moves?

No, the amplitude is constant across the whole file. That keeps the warble a fair test of the system rather than of the signal, but it means a fault that only appears at high levels will not show itself. Run the check again with the amplitude raised if that is a possibility.

Can I use it for hearing checks rather than equipment?

It works as an audible reference, and some clinical testing uses warble tones precisely because a moving pitch is easier to distinguish from a steady one. Treat any result as informal: a proper hearing check belongs with calibrated equipment and a professional, not with a file generated in a browser.

Warble Tone Generator

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Warble Tone Generator sweeps a carrier up and down in a slow, regular wobble, the signal used for decades to check loudspeakers and public address systems. Every control on the page is a plain number, so a repeatable test tone is a few keystrokes away.

What is Warble Tone Generator?

The tone moves above and below a centre frequency at a settable rate, producing the characteristic warble that makes a fault easy to hear when a system is playing it. Set the centre, the deviation, the modulation rate, the duration and the amplitude, then generate a file.

The controls in full:

A centre frequency from twenty hertz to twenty thousand, defaulting to one thousand, which is the middle of the speech and music band.
A deviation from zero to five thousand hertz, defaulting to four hundred, which is how far the tone travels above and below the centre.
A modulation rate from a tenth of a hertz to fifty, defaulting to two, which sets how fast the wobble repeats.
Duration from a tenth of a second to sixty seconds, defaulting to three.
An amplitude slider from one to one hundred percent, defaulting to eighty.

The synthesis is frequency modulation with a sinusoidal modulator, which means the instantaneous frequency of the carrier follows the centre plus the deviation times the sine of the modulation phase. That instantaneous frequency is integrated into a running phase so the waveform itself stays continuous, and the continuity is what keeps the sound clean: building the signal from the frequency directly would make the phase jump at every change and splatter energy across the spectrum as clicks. A warble is therefore a chirp with a slower, more deliberate purpose, and the two tools in this suite share the same underlying arithmetic for exactly that reason. The practice it comes from is worth explaining. A steady tone through a loudspeaker tells you little about how it behaves across the band, but a tone that keeps moving does: any resonance, rattle, buzz or dropout in the system is excited as the warble passes through it, and the fault becomes audible as a change in the sound at the moment the frequency reaches it. That is why the deviation is usually set wide relative to the centre, and why the modulation rate is usually slow enough to be heard as a sweep rather than as a rough buzz. Its second career is as a speaker check that other people can also hear: a wobbling tone is far easier to pick out of a noisy room than a steady one, so an installer can walk the space while it plays and catch a fault by ear without ever reaching for a meter.

Where the signal stops being useful:

The modulation is a sine only, so there is no triangle or random wobble to choose from.
The level stays constant as the pitch moves, so a system with a level-dependent fault will not reveal it here.
The carrier is a pure sine, so the warble contains no harmonics of its own to excite the upper range directly.
Amplitude is a linear percentage rather than a level in decibels.
The file is mono, and capped at sixty seconds, so long soak tests need it looped.
There is no built-in sweep of the centre frequency, which would take the wobble across a wider range.

Use it when a system needs to be exercised across a band of frequencies quickly: checking a speaker for rattles, confirming a public address installation before an event, hunting a resonance in a room or a cabinet, or giving a rehearsal a reference pitch that is easy to hear over other sound. When the movement should be a single pass from one frequency to another instead of a continuous wobble, the sweep tool is the right one, and when it should be faster and more repetitive, the chirp generator is the closest relative.

How to use Warble Tone Generator

Set the centre frequency to the middle of the band you want to exercise.
Set the deviation so the wobble reaches the edges of that band, then choose a modulation rate you can hear clearly.
Set the duration and amplitude, then press generate.
Play the file through the system and listen for rattles, buzzes or dropouts as the tone passes through each frequency.

When to use Warble Tone Generator vs related tools

Warble Tone Generator is built for exercising a system across a band of frequencies while the tone keeps moving, which makes it the practical choice for speaker and installation checks. Chirp Generator performs the same kind of movement at a faster rate over a wider deviation, and Sweep Tone Generator covers the single one-way glide. For a steady reference signal rather than a moving one, Sine Wave Generator and Test Tone Generator are the tools to reach for.

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