Channel check, polarity, bass extension and frequency sweeps — generated live, nothing to download. Find out what your system actually does.
Applies to every test on this page.
Plays a voice-range tone left, then right. If they come out the wrong way round, your cables are swapped — which is commoner than you would think, and it reverses your whole soundstage.
The most common setup fault there is, and easy to miss. In phase should sound like one solid source between the speakers. Out of phase sounds diffuse, wide, and thin in the bass, with no firm centre. If the first button already sounds like the second, one speaker's + and − are swapped at one end.
Sweeps 20–200 Hz over 30 seconds, and the running frequency stays on screen after it ends. Two things to listen for. Where it first becomes audible is where your speakers in your room actually stop, which is rarely the number on the box. And any frequency where it disappears and then comes back is a cancellation — note the number.
A dip that returns is almost never the speaker. It is either a room mode (room mode calculator) or the wall behind the speakers cancelling — the placement tool predicts that one from your front-wall distance, and the two numbers should agree. Move your head half a metre and try again: a room null moves, a speaker fault does not.
20 Hz to 20 kHz over 40 seconds. Should be smooth throughout. A buzz that appears at one frequency and goes away is usually mechanical — a loose driver, a port, or a picture frame.
For hunting down a rattle, or checking one frequency against another.
Equal energy per octave, which is what almost every measurement and calibration routine uses. Useful for level-matching two speakers by ear, and for hearing whether one channel is duller than the other.
A single speaker wired with + and − swapped is the commonest fault in home systems and the easiest to miss, because nothing sounds obviously broken — the bass just goes thin and the centre image falls apart. Compare the two buttons above: if your system already sounds like the "out of phase" one when playing the in-phase test, check the terminals at both ends of both cables.
A speaker quoted to 45 Hz might be perfectly audible at 35 Hz in a small room, because room gain lifts the bottom end, or might disappear by 55 Hz in a large one. The sweep tells you what your system does where it stands. If it stops higher than you would like, the crossover calculator works out where a subwoofer should take over.
If the sweep goes quiet over a range and comes back, hold single tones either side of it — 100 Hz against 150 and 250 Hz, say. A notch is quiet at one and loud at the others; a roll-off gets quieter and stays quiet. Then move your head half a metre and repeat: a room cancellation moves with you, a broken driver does not. And if it sounds right on headphones, the speakers and this page are both fine — it is the room.
Tones are generated by your browser and nothing is recorded or sent anywhere. Bluetooth speakers and headphones may resample or limit the very low frequencies, so use a wired connection for the bass tests if you can.