Surround Sound Test
Play a test sound through one speaker at a time to catch a dead or miswired channel in your stereo, 5.1, or 7.1 setup. Auto sweep runs every channel in order; the bass test checks your subwoofer.
Play each speaker singly from your listening spot. If the sound arrives from anywhere but where the map shows, a cable is swapped.
Can’t place a tone? Switch to pink noise — its full-spectrum hiss is far easier for the ear to locate.
The bass test sweeps 30–120 Hz. A subwoofer that only joins mid-sweep has its crossover set too low.
A surround system rarely fails loudly — it fails quietly. A cable works loose, front and rear pairs get swapped at the receiver, the center channel is muted in a driver setting, or the subwoofer sits powered off, and movies just sound flat with nothing to announce the problem. Playing each channel one at a time is the only reliable way to catch it: the sound comes from where the map says, or it doesn’t. Worth a run after wiring a new receiver, rearranging a room, or updating audio drivers. Nothing to install — the tones are generated locally in your browser.
Each tone is generated with the Web Audio API and routed to exactly one channel, with the others held silent — so a sound from the wrong corner means the wiring, not the test. A stereo device exposes only the front pair; a 5.1 or 7.1 output unlocks the full map. If the surround layouts stay locked, set the output to 5.1/7.1 in your OS sound settings first. Headphones always count as stereo — virtual surround (Dolby Atmos, DTS Headphone:X, Windows Sonic) is applied after this test, so real speaker channels need real speakers.
What if a speaker stays silent or plays in the wrong spot?
Turn the volume up moderately and retry the channel with pink noise, which is easier to place than a tone. Still silent? Check the cable at both ends — speaker terminals and receiver output — and make sure the receiver is in a plain multichannel mode, not a stereo or “direct” mode that folds channels together. Sound from the wrong position almost always means two cables are swapped at the receiver: left/right and front/surround swaps are the classics. A silent subwoofer is usually its own power switch, a turned-down gain or crossover knob, or an LFE cable in the wrong input. If only two channels ever play, the OS is downmixing — set the output to 5.1/7.1 and run the test again.
What each channel carries
| Channel | Where it sits | What it plays |
|---|---|---|
| Front left / right (FL, FR) | Either side of the screen, angled at the listener | Music, effects, and the stereo image — every layout’s workhorses |
| Center (C) | Directly above or below the screen | Dialogue, almost exclusively — a silent center is why voices vanish |
| Subwoofer (LFE) | Anywhere; bass is barely directional | The “.1” — low-frequency effects below ~120 Hz: explosions, rumble, bass drops |
| Surround left / right (SL, SR) | Beside or slightly behind the listener | Ambience and effects that place you inside the scene |
| Rear left / right (RL, RR) | Behind the listener (7.1 only) | Splits the surround field so sounds can pass front-to-back smoothly |