Left and right speaker test
Is the left speaker on the left and the right one on the right? Press a button below and listen.
Press left, right or both to start. Space stops everything.
Sound
Phase
How to run the test
Turn the volume down, then press left. A steady tone should come from your left speaker or earbud only, and the left half of the scope should move while the right half stays flat. Then press right, and finally both.
What the result means
If the sound comes from the opposite side, the channels are swapped: look at the speaker cables, the output settings of your computer or amplifier, and the balance control. If one side is silent or clearly quieter, follow the signal on that side: balance setting, cable, connector, then another device.
If both sides play from the same place, your system may be set to mono audio. Check the accessibility settings, and make sure a Bluetooth device is not in call mode.
Tips for a fair test
Sit in the middle between the speakers, at the same distance from both. Play both with the pink noise setting and listen to whether the sound seems to come from the exact centre. A tone is best for finding a dead channel, noise for judging balance.
Questions
How do I test my speakers with this page?
Turn the volume down low, then press Left. You should hear a steady tone from the left speaker only, and the left half of the scope should move while the right half stays flat. Do the same with Right, then Both.
The tone is a plain sine wave, so a buzz, a rattle or a missing side points to the speaker, the cable or a setting. The keys A, S and D start Left, Both and Right, and Space stops everything.
Only one speaker plays. What should I check?
Play the other channel on the same page. If Left works and Right does not, follow the signal on that side: first the balance slider in your system sound settings, then the cable and the port, then another device.
If the same side stays silent on every device, the speaker or the headphone itself is the likely cause.
Left and right are swapped. How do I fix it?
Press Left. If the sound comes from the right side, the channels are reversed. Check the output settings of your system or audio interface, and how the speaker cables are connected.
With headphones, check that you are wearing them the right way round: the small L and R marks are easy to miss.
One speaker is quieter than the other.
Play Both and listen from the middle between the speakers. If one side is clearly quieter, check the balance slider in your system and in the app you use, then the cable.
Then swap the two speakers' places. If the quiet sound moves with the speaker, that speaker is weaker. If it stays on the same side of the room, the cause is the room or the setup, for example a speaker pushed into a corner.