Check every speaker in a stereo, 2.1, 5.1 or 7.1 system: is it playing, and is it in the right place?
Checking your audio output…
Click a speaker to hear it
Check how deep your speakers go and whether anything rattles.
Need a specific frequency? Use the tone generator.
Sit centered between the pair. Play A and B, then pick the one that sounds fuller and more focused in the middle.
Front left + right
One of them is played with one speaker's signal inverted. That version sounds thin, hollow or hard to place. If it's the one that sounds fuller to you, one speaker is wired backwards.
Sound is made in your browser. Nothing is recorded or uploaded. Testing headphones or earbuds? Use the headphone test.
Pick your layout, then click a speaker in the room to hear it: a short burst of noise plays from that speaker alone, the way a receiver's test tone does. Play all walks around the room, clockwise from front left. The blind check then plays noise from random speakers without saying which and asks where you heard it, which catches a swapped pair you would never notice while you know which speaker should play. The sound is made in your browser and sent straight to your speakers. Nothing is recorded or uploaded.
Before any sound plays, the page asks your browser how many channels the current output accepts. That number is set by your operating system, not by the speakers: a 5.1 system plugged into a computer set to stereo still gets 2 channels, and every test sound comes out of the front pair. Most surround problems are this one setting, so the count is the first thing to check. It tells you what your computer sends, not what your speakers can play.
With the 2.0 layout, Left and Right play from one speaker each. If the voice says left and the sound comes from the right, the cables or plugs are swapped. The Both button plays the same sound from the two speakers at once. A working pair puts it in the middle, between them; if it leans to one side, one speaker is louder, the balance is off, or you aren't sitting centered. Speakers on a desk should be as far apart as they are from your head.
The ".1" is the subwoofer. It plays only low notes, below about 80 to 120 Hz, which is why it sounds like a hum on its own and why the blind check leaves it out: nobody can tell where bass comes from. Most 2.1 computer speaker sets take a stereo signal and split the bass off inside the sub, so they have no separate subwoofer channel. For those, the test plays low notes on left and right, and the sub should pick them up. A 2.1 system on an AV receiver does have its own channel, and the test uses it when your computer is set to 5.1 or 7.1.
5.1 is six channels: front left, center, front right, surround left, surround right and the subwoofer. The center carries most of the dialogue in films. The two surrounds sit to the sides and a little behind you, where ambience and effects come from. If the page sees 6 channels, every speaker is driven on its own, so a dead or swapped speaker shows up in the test instead of being covered by the others.
The standard layout (ITU-R BS.775) puts the center straight ahead, the front pair 30° to each side and the surrounds about 110° to each side, all at the same distance from your seat. The room in the test is drawn to those angles. The sub can go almost anywhere at the front, because low bass doesn't point.
7.1 splits the 5.1 surrounds into two pairs: side speakers level with you, at 90 to 110°, and rear speakers behind you, at 135 to 150°. The most common 7.1 fault is the sides and rears swapped, and on a computer it often isn't the wiring. Windows numbers the 7.1 channels in a different order from films, macOS and most players, and a browser can't tell which order your output uses. The blind check finds out: if sides and rears come out swapped, one switch puts them back for this device.
LFE is the subwoofer's own channel in 5.1 and 7.1. The sub check plays low noise on it, and the bass sweep climbs from 20 to 120 Hz so you can hear where your system starts and whether anything in the room rattles. Small desktop speakers can't play 40 Hz at all; that's physics, not a fault. On a receiver, the Main speakers route sends bass to the front speakers instead. If the sub plays it, the receiver's bass management is moving bass where it belongs. Keep the volume moderate: a sub at full level can bottom out.
Each speaker has a + and a − terminal, and if one of a pair is wired the other way round, its cone moves out while the other moves in. Bass cancels, and voices lose their place in the middle. The check plays the same noise twice on a pair, once normally and once with one side inverted, and asks which sounds fuller. You don't need to know which is which: if you pick the inverted one, one speaker has its wires reversed.
If the page says 2 channels and you have a surround system, your computer is sending stereo. Change the speaker setup of the output your speakers are connected to, come back, and press Check again. The page also checks again when you return to the tab.
If Configure is greyed out or lists only Stereo, the device itself isn't offering more. Over HDMI, that usually means a TV or adapter between the computer and the receiver is reporting stereo; connect the computer to the receiver directly. For analog speakers, install the motherboard maker's audio driver instead of the generic one.
Realtek audio console: set the speaker configuration to match, and turn off Speaker Fill, which copies stereo to the rear speakers and makes every test sound come from everywhere.
Safari may still report only stereo. If it does, use Chrome for the test.
With PipeWire or PulseAudio, a surround profile is all the browser needs. If no surround profile is listed, the card or the HDMI sink isn't offering one.
Some connections carry only two channels, whatever you set on the computer.
| Connection | Channels |
|---|---|
HDMI, computer straight to receiver The best route. Up to 8 channels of uncompressed sound. Set the HDMI output to 5.1 or 7.1. | 5.1 and 7.1 |
HDMI through the TV, ARC ARC can't carry multichannel sound from a browser. It passes stereo, or compressed Dolby Digital from apps that send it, which a web page doesn't. | Stereo only |
HDMI through the TV, eARC eARC carries uncompressed multichannel sound, as long as the TV passes it on. Check the TV's audio output setting (Passthrough or Auto). | Usually 5.1 and 7.1 |
Optical or coaxial (S/PDIF) S/PDIF carries two channels of uncompressed sound. 5.1 over it needs a sound card that encodes on the fly (Dolby Digital Live or DTS Interactive). Then the computer shows a 5.1 output and this test works. | Stereo only |
Analog jacks on a PC Green is front, black is rear, orange is center and subwoofer, grey is side (7.1 only). Set the speaker configuration to match in your sound settings or the audio console.
| 5.1 and 7.1 |
USB sound card or gaming headset A 5.1 or 7.1 USB card drives real speakers. A 7.1 headset shows up as 8 channels and its software turns them into virtual surround on two earcups. | Depends on the device |
Bluetooth Bluetooth audio is two channels. A surround soundbar connected over Bluetooth spreads that stereo over its speakers, so the test can't address them one by one. | Stereo only |
A soundbar with separate rear speakers and a sub can be tested channel by channel only if the computer sees 6 or 8 channels, which means HDMI straight into the bar or eARC through the TV. Over ARC, optical or Bluetooth the bar gets stereo and decides for itself what each speaker plays. A bar without rear speakers creates surround virtually, so a test sound can come from roughly the right direction without any real speaker there.
To compare, Windows has its own per-speaker test: in mmsys.cpl › Configure, click a speaker in the diagram. If it plays there but not here, tell us through the feedback button.
Check that every speaker cable went to the right terminal, and test the computer → HDMI → receiver chain that the receiver's own test tone doesn't cover.
Find out whether Windows is sending surround at all, which plug is in which jack, and why the rears are silent.
Check that the driver exposes 8 channels and that each one lands where the virtual surround says it should.
See whether your connection carries real channels or stereo that the bar spreads out by itself.
Make sure left is left, the sub plays, and nothing on the desk buzzes at a particular bass note.
Run the blind check and the polarity check, and paste the result into a ticket or forum post.
The page will say 2 channels. Your computer is set to stereo, or the connection carries only stereo. Follow the setup steps above.
Something is spreading stereo to all the speakers: Realtek Speaker Fill, or a receiver mode such as All Channel Stereo, Multi-Channel Stereo, Dolby Surround or DTS Neural:X. Switch the receiver to Direct, Pure Direct or Straight while you test.
The most common home theater wiring mistake. Swap the two cables at the receiver end. In 7.1, if sides and rears are swapped instead, try the Swap sides and rears switch first: it is usually the channel order, not the cables.
Check that the computer is set to 5.1 or 7.1, not to quad, which has no center. On a receiver, the center must be set to Small or Large, not None. On PC jacks, the center and sub share the orange jack and a split cable; if the center plays bass and the sub says 'Center', the split is reversed.
Swap it with a working speaker of the same kind. If the silence follows the speaker, the speaker or its cable is at fault; if it stays at the same position, check the receiver's output and its speaker setup.
One speaker of a pair is probably wired + to −. Run the polarity check, then look at the red and black wires on both ends of that speaker's cable.
Check the system volume and mute, and that the output named under the channel count is the one your speakers are on. On an iPhone, flip the silent switch off: it mutes web audio. On a receiver, make sure the input matches the computer's HDMI or analog input.
Turn the test level and your system volume down. If one speaker still crackles at a low level, check its cable and connections for loose strands, then swap it with another speaker to see whether the fault moves.
The content is stereo. YouTube in a browser plays stereo, and many games output stereo unless you choose 5.1 or 7.1 in their audio settings. Your receiver's Dolby Surround or DTS Neural:X mode can spread stereo content to all speakers if you want that.