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Speaker Distortion Analyzer

Hunt rattles, buzzes and driver distortion by ear. Play a slow logarithmic sweep, park a sustained tone on any frequency, or run an increasing-amplitude stress ramp — then mark the frequency where you hear a problem. An optional microphone mode draws the live spectrum and a rough harmonic-energy indicator.

Safe-volume warning. Loud, very-low and rising-level tones can damage drivers and your hearing. Start at a very low level, keep it low, and stop the instant anything sounds harsh, rattly or clipped — especially in the stress mode, which deliberately ramps the level up. This is an uncalibrated listening aid: it helps you find and locate audible noises, but it cannot measure calibrated THD or absolute distortion. The optional mic view is indicative only — your speaker and microphone each add their own distortion, and the browser may apply AGC/limiting. For a real distortion measurement use a measurement microphone with software like REW or an audio analyzer.

Now playing:
Choose a mode and press Play. Start at a very low level.

Marked frequencies

How It Works

Most audible speaker faults are mechanical: a loose grille or cabinet panel, a port that chuffs, an object on a nearby shelf that resonates, or — inside the driver — a rubbing voice coil, a torn surround, or a cone being pushed past its limits. These buzzes and rattles only appear at the particular frequency that excites them, so the reliable way to find them is to sweep a clean tone across the whole range and listen. This tool plays that tone with the Web Audio API (an oscillator routed through a gain control to your speakers or headphones), so the signal itself is mathematically pure — any rattle, buzz or harsh edge you hear is coming from the speaker, the cabinet, the room, or something loose nearby, not from the test signal.

There are three ways to drive it. The log sweep glides slowly from 20 Hz to 20 kHz over a duration you choose; when you hear a noise you press Mark and the current frequency is logged so you can return to it. The sustained tone lets you park on one frequency (or on a marked one) and listen closely, nudging the slider a little either side to confirm exactly where the rattle peaks. The stress ramp holds one frequency while slowly increasing the level, which makes a marginal rattle or the onset of driver distortion easier to provoke — but because rising level is exactly what damages drivers and ears, it starts very low, is capped a few dB below full scale (about -5 dBFS) — still potentially very loud — and should be stopped the moment anything sounds wrong.

The optional microphone mode captures the sound in the room and draws its spectrum, marking the fundamental (f) and its harmonics (2f, 3f…). When energy piles up at those harmonics relative to the fundamental, it suggests distortion, and the tool shows a rough percentage as a guide. Be honest with yourself about what this can mean: a laptop or phone speaker is already a distorting source, the built-in microphone adds its own non-linearity and frequency colouration, and browsers often apply automatic gain control or limiting that you cannot fully disable. So the harmonic indicator is a relative, uncalibrated hint — great for spotting a speaker that grossly distorts, useless as a real Total Harmonic Distortion (THD) figure. For a number you can trust, use a calibrated measurement microphone with software such as REW, or a dedicated audio analyzer, on a known-clean playback chain.

Frequently Asked Questions

Does this measure my speaker's THD or distortion percentage?
No. It is an uncalibrated listening aid for finding and locating audible rattles, buzzes and gross distortion. The optional mic view shows a rough harmonic-energy hint, but your speaker and microphone each add their own distortion and the browser may apply AGC or limiting, so it is indicative only — not a calibrated THD measurement. For a trustworthy figure use a measurement microphone with REW or a dedicated audio analyzer.
I hear a buzz — is it the speaker or something else?
Not necessarily the driver. A buzz at one frequency is very often a loose grille, a cabinet panel, a port chuffing, or an object elsewhere in the room resonating sympathetically. Mark the frequency, switch to the sustained tone to hold it, then gently press or move suspect parts and nearby objects: if the buzz changes or stops, you have found the culprit. A noise that follows the driver everywhere and worsens with level is more likely cone, surround or voice-coil distortion.
Is the stress ramp safe for my speakers?
Use it with care. It deliberately increases the level to provoke marginal rattles and the onset of distortion, and loud — especially low — tones can overheat voice coils or mechanically damage a driver, as well as harm your hearing. It starts very low and is capped a few dB below full scale (about -5 dBFS) — still potentially very loud — but you must start at the lowest setting and stop the instant you hear anything harsh, distorted or rattly. Never run it loud for long, and protect your ears.
Why does the mic show harmonics even on a good speaker?
Because the whole chain distorts a little. Consumer and built-in speakers are non-linear, the microphone adds its own harmonics and colours the frequency response, and browser audio processing can clip or compress the signal. So some harmonic energy is expected and does not by itself indicate a fault. Look for large, obvious harmonic build-up that rises with level and tracks one speaker — and treat the percentage as a relative hint, not an absolute number.
Can it test surround (5.1/7.1) speakers individually?
Only the front left and right reliably. Browser audio output is stereo (two channels), so the test signal plays to the L/R pair. There is no dependable way for a web page to address discrete 5.1 or 7.1 channels, so it cannot drive a centre, surround or height speaker on its own. To distortion-test individual surround channels, use your receiver's built-in test-tone generator or a dedicated multichannel test signal.