Speaker Test

Play a tone from the left speaker, the right, or both, and make sure each one is working.

Check the balance

Once you know both speakers work, check that they're working equally. This sweeps a tone smoothly from left to right. You can also jump straight to hard left, centre or hard right, to compare one side directly with the other.

Tones here play at -20 dBFS, which means 20 dB below the loudest level the signal can reach. That says nothing about how loud it sounds in your room. Your browser can't know that, so we don't pretend to.

What a quiet side does and doesn't tell you

If one side is silent or quieter, something between your device and that speaker isn't passing the full signal. This test can't tell you what. It could be the speaker itself, a loose or damaged cable, a balance setting pushed to one side, or an output that's muted. All four sound the same here. What the test does is narrow it down to one side. To find the culprit, swap the suspect speaker onto the other output, or try a different cable. Dead, Blown or Miswired: Diagnosing a Silent Speaker walks you through that swap and what to listen for.

Why a tone and not a song?

Music is mixed differently on each side on purpose: a guitar on the left, backing vocals on the right, reverb that's never quite even. Play a song through one speaker at a time and each side will sound different, even when both speakers are perfectly fine. A single tone sends exactly the same signal to both sides, so any difference you hear comes from your equipment, not the music.

Check your balance and mono settings first

Before you blame a speaker, check the software. A left/right balance slider only has to be nudged once, and it'll favour one side until someone notices. On Windows, go to Settings → System → Sound, pick your output device, and look for the balance control under its volume options. It's easy to knock with a mouse and easy to forget it's there.

Also look for a mono setting. Windows has a "Turn on Mono Audio" option in its accessibility settings, and macOS has a "Mono Audio" toggle under Accessibility → Audio. They're there for people who hear in only one ear, and they mix both channels into one. Left on by accident, they make every stereo test on this page sound the same on both sides. Your speakers are fine; the computer is merging the sound before it reaches them.

Testing earbuds rather than speakers? Why is one earbud quieter than the other covers the same balance setting on iPhone and Android, plus the far more common culprit: earwax blocking the mesh.

Checking the earpiece on your phone, the small speaker you hold to your ear on calls? A web page can't play sound through it, but here's how to test your phone's earpiece with the phone itself.

What the centre check tells you

Play the tone hard left, then hard right, then centred, and notice where the centred one seems to come from. With two working speakers playing the same signal, your ears create a "phantom" sound right in the middle, between the speakers. That only happens when both sides match in loudness and in timing (phase). A balance problem throws off the loudness. A speaker wired backwards throws off the phase, which sounds quite different, and that's what the polarity check is for. This test only checks that both sides are equally loud.

Bluetooth speakers, soundbars and laptops

Many Bluetooth speakers, soundbars and laptops tell your computer they're stereo, but have only one speaker inside, or two so close together you can't hear any separation. On those, "both sides sound the same" is the right result. Nothing's broken; there was never any real separation to hear. For true stereo you need two separate speakers with some space between them, whatever the device calls itself.

Sit in the middle

This test assumes you're sitting halfway between your speakers. Move to one side and the nearer speaker will sound louder and arrive a little sooner, just because it's closer. That sounds exactly like a balance fault, but it has nothing to do with your equipment. If one side seems louder, sit in the middle, face forward and try again before deciding anything's wrong.

Not sure where the problem is? Run the full sound check. It's six quick questions, and at the end it tells you which tool to use next.