What the sound test checks
A stereo system has two jobs. It has to put the right sound in the right place, and it has to reproduce the full range of pitch. This page tests both with short, simple signals you can judge by ear. You do not need any special gear.
| Button | What you hear | What it proves |
|---|---|---|
| Left | Chimes on the left channel only | Left speaker works and is wired to the left output |
| Right | Chimes on the right channel only | Right speaker works and is on the right output |
| Centre | Chimes panned to the middle | Both speakers play at the same level; image sits between them |
| Stereo sweep | A tone gliding left, right, then left again over 6 seconds | Smooth panning, no gaps or jumps in the stereo field |
| In phase | Pink noise, same signal in both channels | Both speakers push air the same way |
| Out of phase | Pink noise, right channel inverted | Hollow, wide sound confirms polarity checks work |
| Bass 20 to 200 Hz | A tone gliding up over 12 seconds, with Hz shown | How low your speakers go and where buzzing starts |
| Hearing range 8 to 20 kHz | A rising high tone over 24 seconds | The highest pitch you can still hear |
Pink noise is a hiss with equal energy in every octave. It sounds like steady rain and is the standard signal for comparing speakers, because it excites low, mid and high drivers together.
Left, right and centre
Start with the basics. Press Left and listen. The chimes should come from the left speaker or the left ear cup, and nothing should leak from the other side. Then press Right. Finally press Centre. The sound is split equally between both speakers, so your brain places it in the middle, between the two.
If the Left button plays on the right, your channels are swapped. If Centre sounds off to one side, the balance is off, either in the system settings or in the speaker itself. If one side is silent, skip to the troubleshooting table below.
Sit about as far from the speakers as they are apart, with your head in line with the middle. That forms the classic listening triangle. At desk distance, a laptop is a tiny version of the same set-up.
The stereo sweep adds movement. A single tone slides from the left speaker to the right and back in six seconds. Listen for steady loudness the whole way. A dip in the middle may mean one speaker is quieter. A click or jump suggests a loose cable or a fault in the output.
Polarity: in phase and out of phase
A speaker cone moves forward and back. Polarity says which direction it moves when the signal goes positive. If two speakers are wired opposite ways, one pushes while the other pulls. The sound cancels where they overlap, and bass in particular goes thin and weak.
The test plays pink noise twice. In phase sends the same signal to both channels. Out of phase flips the right channel. Compare them.
| Test | Healthy system | If polarity is reversed |
|---|---|---|
| In phase | Focused, solid and full, with a firm centre and good bass | Wide, hollow and thin, with weak bass |
| Out of phase | Wide, diffuse and hollow, with weak bass | Focused and full, because the wiring flip cancels the inversion |
In plain words, the in-phase noise should sound better than the out-of-phase noise. If it is the other way round, one speaker is likely wired backwards. Check the red and black connections at the amplifier and at the speaker. Each red terminal should join red, and each black should join black.
Do the test with your head in the middle and then move closer to one speaker. With the right polarity, in-phase noise stays solid as you move. With bad polarity, you hear a hole in the bass at the centre.
Bass sweep: how low do your speakers go
The bass sweep glides a tone from 20 Hz to 200 Hz in 12 seconds and shows the current frequency on screen as it plays. Watch the number and write down where you start to hear the tone clearly. That is a rough guide to your speakers' low-end limit.
| Speaker type | Typical lowest clear note | What to expect from the sweep |
|---|---|---|
| Phone speaker | About 300 to 500 Hz | Silent until the top of the sweep |
| Laptop speakers | About 100 to 200 Hz | You hear the end of the sweep only |
| Small desktop speakers | About 60 to 80 Hz | Tone appears around 70 Hz |
| Bookshelf speakers | About 45 to 60 Hz | Clear from 50 or 60 Hz |
| Floorstanding speakers | About 30 to 40 Hz | Clear from 35 Hz |
| With a subwoofer | About 20 to 30 Hz | Heard as pressure from 25 Hz |
The figures are typical, not guarantees. Room shape matters as much as the speaker. In a small room, some frequencies will boom and others will almost vanish. If the tone seems to jump in volume in one spot, you have found a room resonance.
Buzzing or rattling during the sweep points to something loose: a shelf, a cabinet door, a speaker grille, or a torn cone. Fix it by tightening, padding or moving the item. Distortion that is built into the speaker will sound like a crackle that gets worse as you raise the volume.
Hearing range sweep
The last sweep climbs from 8 kHz to 20 kHz over 24 seconds. Press the button marked 'I can't hear it any more' at the moment the tone disappears. The page records the frequency and shows it as your upper limit.
The result depends on your ears and your gear. A pair of speakers that rolls off at 16 kHz will give you a lower number than your ears can reach. Run the test with headphones too, and compare. If the two numbers match, the limit is probably in your ears.
Do not push the volume to hear more. Raising the volume does not widen your range, it only risks damage. This is a fun check and not a medical hearing test.
| Upper limit you record | What it usually means |
|---|---|
| Above 18 kHz | Typical of younger ears with good gear |
| 15 to 18 kHz | Normal for many adults |
| 12 to 15 kHz | Common after 40 or 50, or from speakers that roll off early |
| Under 12 kHz | Repeat with headphones; if it stays low, consider a hearing check |
Troubleshooting: sound problems and fixes
If a test result looks wrong, match the symptom in the first column. Most problems are settings or cables, not broken speakers.
| Symptom | Likely cause | Fix |
|---|---|---|
| No sound on the right side | Balance slider off-centre, loose plug, or mono-left only cable | Reset balance to centre, reseat the plug, try another cable or port |
| No sound on the left side | Same as above, or a dead driver | Swap the cables left to right; if the silence stays on the same speaker, the speaker is faulty |
| Left and right swapped | Cables crossed, or an app that flips channels | Switch the plugs or the speakers; check the audio settings for a channel-swap option |
| Thin sound and weak bass | One speaker wired with reversed polarity | Match red to red and black to black at both ends |
| Same sound in both ears or speakers | Mono audio setting turned on | Turn off mono audio in your accessibility settings |
| Crackle or hiss | Dirty jack, bad cable or ground loop | Clean the jack, try a new cable, plug both devices into the same outlet |
| Tone cuts out during a sweep | Power saving, audio enhancement, or a loose plug | Disable enhancements and power saving, reseat the plug |
| Very low volume | System volume low, or a quiet output set by the OS | Raise the system volume, check the per-app volume mixer |
Mono audio deserves its own note. Windows, macOS, iPhone and Android all have an accessibility option that mixes left and right into one signal. It helps people with hearing loss in one ear, but it breaks every stereo test. Look under Accessibility, then Audio, in your system settings. The exact menu names differ between versions.
Pass or fail: the 8-item checklist
Use the checklist on the page to mark what you hear. Be strict. A real fault does not fix itself, so every failed item is worth chasing.
- Left plays on the left side only.
- Right plays on the right side only.
- Centre sounds in the middle, between the speakers.
- The stereo sweep moves smoothly with no jump or dip.
- In phase sounds more focused and full than out of phase.
- The bass sweep is clean, with no buzzing or rattles.
- You can hear the bass tone from the frequency you expect for your speakers.
- No crackle, hiss or dropout at normal volume.
Eight ticks means your system is working properly. Fewer ticks means something to fix, and the table above tells you where to start.
Laptops, phones and PCs
The test works on every device with a browser. Differences between devices are mostly about where the speakers are and how big they are.
- Laptops. The speakers are tiny and often fire from the sides or the bottom. Expect little below 150 Hz and a narrow stereo image.
- Phones. A phone speaker may be mono. Use headphones for left and right tests, and rest the phone on a table so it does not rattle.
- Desktop PCs. Check the output you chose in the sound panel. HDMI, USB and the 3.5 mm jack can each be a different device.
- Bluetooth speakers. A single Bluetooth speaker is usually mono. A pair set up as stereo should pass the Left and Right test.
Other tools on this site can help once your system sounds right. You can split vocals at /vocal-remover/ and find a song's BPM at /bpm-finder/. Test your gear first and your mix decisions will be easier to trust.
Frequently asked questions
How do I test my speakers online?
Press Left, then Right, then Centre, and check that each sound comes from the right place. Then run the stereo sweep, the in-phase and out-of-phase noise, and the bass sweep. Tick the 8-item checklist as you go. Everything plays in the browser, so you need nothing else.
Does the sound test record me or upload anything?
No. The page does not use your microphone and does not upload any audio. All tones and noise are generated inside your browser while you listen. When you close the tab, nothing is stored on any server.
Why does the sound come from the wrong side?
Your speaker cables may be swapped, or an app or setting may be flipping the channels. Check that the left speaker is plugged into the left output. Then look in your audio settings for a channel swap or balance control. Reverse the plugs if needed.
What does the in-phase and out-of-phase test show?
It checks polarity. Both channels carry the same pink noise in the first test, and the right channel is inverted in the second. A healthy pair sounds fuller and more focused in phase. If it is the other way round, one speaker is probably wired backwards.
My bass sweep is silent at the start. Is that a fault?
Probably not. Most laptop and small desktop speakers cannot play below 60 to 100 Hz, so the first part of the sweep is inaudible. Watch the frequency display and note when you begin to hear the tone. That is your speaker's practical low limit.
Why are both speakers playing the same sound?
A mono audio option is probably switched on. Windows, macOS, iPhone and Android all have one in the accessibility settings. It mixes both channels into one. Turn it off and run the Left and Right test again.
What frequency range can I hear in the hearing sweep?
Young people can hear up to about 18 to 20 kHz, and many adults stop hearing between 14 and 17 kHz. Your result also depends on your speakers or headphones. Use it as a rough check and not as a medical test.
Is it safe to run the sweeps loudly?
Keep the volume at a normal, comfortable level. High and low sweeps can sound quiet and then suddenly loud, and loud tones can damage hearing or small tweeters. Start low, raise the volume slowly, and stop if anything hurts.
Does it work on a phone?
Yes. It runs in a phone browser. The speaker on most phones is small and may be mono, so use headphones or an external speaker for left and right checks. The bass sweep will be mostly silent on a phone speaker.