Audio / Device checks
Speaker Test: Left/Right, Stereo, Bass, and Phase
Test your speakers and headphones in the browser: play beeps on the left and right channels, a centred sound, a bass sweep from 30 to 150 Hz, and an in-phase and out-of-phase noise test that reveals reversed speaker wiring.
Speaker Test: Left/Right, Stereo, Bass, and Phase: Left and right beeps are panned fully to one channel, so they show whether the channels are swapped. The bass sweep rises slowly from 30 to 150 Hz, so you can hear where your speakers start to produce sound. The phase tests play the same noise in both channels, with one channel inverted in the second: correctly wired speakers sound focused in phase and diffuse out of phase. Runs 100% locally in your browser with zero server file uploads.
- Category
- Everyday tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
Turn your device volume down before you start, then raise it slowly. High-pitched and loud tones can damage hearing and speakers.
If left and right are swapped, check the cable or the speaker positions. In the phase test, out of phase should sound diffuse and hard to place; if it sounds more focused than in phase, one speaker is wired with plus and minus reversed. Each test stops by itself after 10 seconds.
Bluetooth and laptops
Some Bluetooth headsets switch to mono when the microphone is in use, and many laptops mix the channels below a certain frequency, so a left or right test may sound from both sides at low volume.
After the test
To check the other end of a call, use the mic test, and for a single frequency or a full sweep, the tone generator.
How to use it
- Lower the volume and choose a test.
- Listen for the sound on the expected side, or for the change between tests.
- Stop the test, or let it stop after 10 seconds.
Privacy & limitations
Sound is generated in your browser.
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Frequently asked questions
Left and right are swapped. What now?
Check that the left speaker is plugged into the left output, that headphones are not on backwards, and that no balance or mono setting is on in the system sound settings.
What does out of phase mean?
One speaker pushes while the other pulls, so bass cancels and the sound loses its centre. If the out-of-phase test sounds more focused than the in-phase one, swap the plus and minus wires on one speaker.
Why can't I hear the bass sweep at first?
Most small speakers produce little below 60 to 100 Hz; the frequency where it becomes audible is roughly your speakers' lower limit.
Free tool · runs in your browser · no account required