Left and right speaker test
Stereo audio test for speakers and headphones. Start with your volume low.
Last updated: (originally published )
Left and right speaker test
Start at a low volume. A steady tone at a high level is uncomfortable and can damage hearing.
Stereo balance
Pan the sound between the two sides while a tone or noise plays. Use it to confirm that both sides reach the same loudness. Balance applies when both channels are selected.
Frequency sweep (20 Hz to 20 kHz)
A slow rise through the hearing range. Listen for a band that disappears, buzzes or rattles.
Bass and subwoofer check
Deep tones expose loose drivers, rattling cabinets and blocked earbud meshes. Keep the level low: small speakers distort rather than reproduce these frequencies.
White and pink noise
Full-spectrum noise makes a channel imbalance easier to hear than a single tone. Pink noise has equal energy per octave and sounds more even to the ear than white noise.
Built by Nayeem, Software Developer of SoundLevelTest.com
Latest update: Added a left/right audio test checklist with expected results per device, plus new answers on headphone channel checks, Bluetooth mono and stereo testing.
Play a tone through the left channel, the right channel or both to check that your speakers, headphones or earbuds are working and correctly balanced, then run a 20 Hz to 20 kHz sweep, sub-bass tones or pink noise to find weak spots. This tool plays sound — it does not measure it. To measure how loud a room is, use the sound level test.
Left/right audio test: what you should hear
| Button | Working result | If not, check |
|---|---|---|
| Test left speaker | Sound only from the left speaker or left earbud | Swapped cables, headphones worn reversed |
| Test right speaker | Sound only from the right side | Loose plug, dead driver, balance slider |
| Test both (stereo) | Tone appears centred between both sides | Mono setting, Bluetooth call mode, uneven volume |
Questions people ask
How do I check my left and right speakers?
Set your volume low, press Test left speaker and confirm the tone comes only from the left side, then press Test right speaker. Finish with Test both (stereo): the tone should sit in the centre.
How do I test left and right on headphones or earbuds?
Wear them the normal way round (L on the left ear), then play each channel separately. If the left tone appears in your right ear, the headphones are reversed or a channel-swap setting is on.
Why do I hear both channels in one ear?
Usually a mono audio accessibility setting is on, or a Bluetooth headset has switched to hands-free call mode, which is mono. Turn off mono audio and pick the stereo version of the device in your sound settings.
Why test my speakers?
A channel test finds a dead driver, a half-inserted plug, a swapped left/right cable or a Bluetooth device that has dropped to mono, in a few seconds and before an important call or a listening session.
Does this speaker test work on phone speakers?
Yes, though most phones have a single speaker or two very closely spaced ones, so left and right may sound almost identical. Plug in headphones for a meaningful channel test.
Why does one side sound different?
Common causes are a balance setting shifted in your operating system, a worn cable, debris in an earbud mesh, or one speaker placed closer to a wall. Low frequencies expose driver problems most clearly, so try 100 Hz and 250 Hz as well as 1 kHz.
What frequency range does the sweep cover?
The sweep rises logarithmically from 20 Hz to 20,000 Hz over 5, 10 or 20 seconds, with the current frequency shown live so you can note where a speaker becomes faint or starts to buzz.
Is the speaker test free and private?
Yes. It runs entirely in the browser using the Web Audio API, with no account, no install and no recording. It only plays sound; it does not use your microphone.
How to run the test properly
Start with your system volume low, choose 1 kHz, and play the left channel alone. A healthy channel produces a steady tone with no rattle, crackle or dropout. Repeat on the right channel and listen for a difference in loudness or tone rather than an obvious failure, since a partly damaged driver usually sounds thinner rather than silent. Finish with both channels to confirm the image sits centred between the speakers or between your ears.
Then sweep the frequency buttons. Low tones reveal loose drivers, buzzing enclosures and blocked earbud meshes; high tones reveal a failing tweeter or heavy audio processing. If a fault appears on only one source, test the same device with another app or another cable before assuming the speaker itself is at fault.
What the test cannot tell you
This page confirms that channels work and that both sides behave alike. It does not measure frequency response, distortion or output level, because the browser has no reference for what leaves your speakers. Perceived loudness also varies by frequency, so a 100 Hz tone can sound quieter than a 1 kHz tone at an identical setting without indicating any defect.
Keep sessions short and the level comfortable. A sustained pure tone is more fatiguing than music at the same setting, and a high level through headphones can be harmful. If you want to know how loud a room or a device actually is, use the meter rather than judging by ear.
Troubleshooting common results
- No sound at all: check that the correct output device is selected in your system sound settings, that the tab is not muted, and that the volume is above zero. Some browsers only start audio after a click on the page.
- Left and right are swapped: check how headphones are worn and how speaker cables are connected to the amplifier, then check any channel-swap option in your audio driver.
- Both channels play from one side: look for a mono audio or accessibility setting in your operating system, and confirm a Bluetooth device is not in a hands-free call mode.
- Crackling or dropouts: try a wired connection, close other audio apps, and move a Bluetooth device closer to reduce interference.
How to read the frequency sweep
The sweep rises smoothly from 20 Hz to 20,000 Hz, so a fault shows up as a change during the rise rather than as silence. Below roughly 60 Hz most laptop and phone speakers produce almost nothing, which is normal. A sudden buzz in the lower range usually comes from the cabinet, the desk or a loose grille rather than the driver itself. A section that drops out in the middle of the sweep points to a crossover or driver problem, and a sweep that fades early near the top is often the limit of your own hearing: adults commonly stop hearing tones somewhere between 14 kHz and 17 kHz.
Run the sweep once per side. Comparing where each side becomes faint is a more reliable check than listening to both together, because the stronger side masks the weaker one.
Checking balance and phase with noise
Pink noise contains every frequency at once, so an imbalance is easier to hear than with a single tone. Play pink noise through both channels and move the balance slider slowly from side to side: the sound should feel equally loud at matching positions left and right. If the centre position pulls towards one speaker, check the balance setting in your operating system before suspecting hardware.
If both speakers work individually but the two together sound thin and the bass disappears, the wiring of one speaker may be reversed, so the two cones move in opposite directions and cancel each other. Swapping the two wires on one speaker terminal usually restores the low end.