Speaker and Headphone Test
Which side is which, whether they are wired the same way, and how low they go.
Runs entirely in your browser
Loading the tool…
Turn your volume down first, then press a side. The tile lights on the side that should be playing: if the sound comes from the other one, left and right are swapped.
Are the speakers wired the same way round?
Play both, one after the other. In phase should sound solid and centred between the speakers; out of phase should sound thin and hard to place. If it is the other way round, one speaker has its two wires swapped.
Frequency sweep
A tone gliding from low to high. Note where the speaker starts making a sound and where you stop hearing it. Keep the volume low: the top end is piercing to anyone who can still hear it.
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- —Output channels
- —Sample rate
- —Output latency
Press Left and the sound should come from the left. It sounds too obvious to need testing until you have a pair of headphones on backwards, a car stereo wired by someone in a hurry, or a desk where the speakers were set up the other way round. This page plays one channel at a time, the left with nothing at all on the right, so there is no doubt about which side a sound belongs to.
The sound is pink noise by default, in short bursts. Noise is far easier to place than a pure tone, which tends to seem to come from everywhere at once in a small room, and bursts are easier to place than a drone.
The phase check finds the fault the channel test cannot: a speaker with its two wires swapped. It still plays, but pushes when its partner pulls, and the bass cancels between them. Played in phase, a correctly wired pair puts the sound in a solid point between the speakers; out of phase, it goes thin and seems to come from nowhere. If the two buttons sound the wrong way round, one speaker is wired backwards.
The sweep glides from 20 Hz to 20 kHz, spending the same time on each octave, and shows the frequency as it goes. Where a small speaker first makes a sound is its real bass limit, whatever the box says. Where you stop hearing the top is your own hearing, not the speaker: it falls with age, and most adults stop somewhere between 12 and 17 kHz.
How to use it
- Turn the volume down, then press Left, Centre and Right in turn.
- Play In phase and Out of phase one after the other and compare.
- Run the sweep and press Stop where the sound disappears.
Questions
The sound comes from the wrong side. What is wrong?
The channels are swapped somewhere between this page and your ears. With headphones, check they are on the right way round: the left cup is usually marked L. With speakers, swap the cables at the back of the amplifier or computer, or swap the speakers themselves. A Bluetooth device can also swap them in its companion app.
I hear both sides when only one should play.
Something is mixing the output to mono. Windows has a Mono audio switch under accessibility settings, macOS has one under Accessibility, Audio, and phones have the same option. A single Bluetooth speaker is mono by design, and so is most laptop audio below a certain size, which the channel count under the tests will show as 1.
What does the phase test actually check?
That both speakers move the same way for the same signal. Each speaker has a positive and a negative wire, and if one is connected backwards its cone moves out while the other moves in. The two then cancel each other's bass, and the sound loses its centre. The out-of-phase button deliberately inverts one side, so you know what wrong sounds like.
Why can I not hear the top of the sweep?
Probably because nobody over about twenty can. The highest frequency people hear drops with age, from around 20 kHz in childhood to 12 to 15 kHz for many adults, and that is normal rather than a hearing problem. Try the sweep with a younger person listening: if they hear it and you do not, the speaker is fine.
Is this a hearing test?
No. It can show roughly where your hearing stops at the top, but a real hearing test uses calibrated equipment at controlled levels in a quiet room, and checks each ear at many frequencies and volumes. If you are worried about your hearing, see an audiologist.
Can this damage my speakers or ears?
At a sensible volume, no. Start low and turn up. Two things are worth care: the very bottom of the sweep can make small speakers rattle at high volume, and the top of it can be unpleasant to young ears at a level an adult cannot even hear. The page starts at a low volume for that reason.
Does anything get recorded?
No. This page only plays sound, made on the spot by your browser's own audio engine. It never asks for the microphone, and it is served with a header that stops it opening a connection to anywhere.
Your data stays on your device
Everything above runs inside your browser as WebAssembly compiled from Rust. Nothing you type is uploaded, logged or stored on a server. You can load this page once, go offline, and it still works.
This page makes no requests at all, to anywhere. That is not a promise in the copy: it is a Content-Security-Policy header your browser enforces, and connect-src on it is none. Open the network tab and watch nothing happen.