Speaker test

Use the channel buttons. Each one plays a short burst on one side only, so you can confirm which speaker is which and that both are alive.

The most common finding is a stereo pair wired the wrong way round, which is invisible until you test it and quietly ruins every film and game you have played on that setup.

Check in this order: the balance control in your operating system sound settings, the cable seated fully at both ends, a different port or device, and a different pair of headphones in the same port.

If one side is dead on every device, the output is at fault. If it follows the headphones to another device, the headphones are at fault. That single swap tells you which thing to replace.

It plays a continuous tone that climbs from a deep bass note to the top of the audible range, so you hear your whole system in one pass.

It shows two separate things: where your hearing stops, and where your speakers stop. A rattle at a particular frequency is a loose driver or cabinet. A clean fade out at the top is normal for both ears and equipment.

Almost certainly age, and it is completely normal. Human hearing is often quoted as 20 Hz to 20 kHz, but that upper figure describes healthy young ears. Most people in their thirties top out around 15 to 16 kHz and it keeps falling.

Small speakers and phone speakers also roll off early, so if you cannot hear 60 Hz on a laptop that is the laptop rather than your ears.

At sensible volume, yes. The risk is at high volume: a sustained sine wave puts far more continuous energy into a driver than music does, and tweeters are the first thing to fail.

Keep the level moderate, keep sustained tones short, and never start a sweep with headphones already on your ears.

Yes, all of them. The test plays through whatever your system currently uses for output, so select your headphones as the default device first.

Bluetooth adds noticeable delay between pressing a button and hearing the tone. That lag is the wireless link, not a fault, and it does not affect the channel or frequency results.

Where the browser allows it, yes, and an output picker appears. Chrome and Edge support choosing an output device from a web page; Firefox and Safari generally do not.

When no picker is available, change your default output in system sound settings and the test follows it.

Crackling that appears at every frequency usually means a buffer problem on the computer rather than the speaker: a busy CPU, an aggressive power saving setting, or a driver that needs updating.

Crackling that only appears around certain frequencies, or that you can make worse by touching the cable, is physical. A damaged cable, a loose connector or a torn driver all sound like that.

Browsers suspend audio until you interact with the page, so the first press both starts the audio engine and plays the sound. Later presses respond immediately.

Bluetooth output adds its own delay on top, typically between 100 and 300 milliseconds depending on the codec.

It tests function rather than fidelity: which channel is which, whether both work, whether anything rattles, and how far the system reaches at each end of the range.

Judging tonal quality needs a measurement microphone and a treated room. What this page reliably catches is the faults that matter: a dead side, a swapped pair, a buzzing driver, or a device that quietly collapsed to mono.