Surround Sound Test

Step through each speaker of a 5.1 or 7.1 system in turn, one at a time, and confirm the sound comes from where it should — not from whichever speakers happen to be closest to the front.

Why there is a "Check my output" button

A browser cannot ask the operating system how many channels the current output device supports until it has created an AudioContext, and an AudioContext can only be created inside a genuine user gesture — a rule every browser enforces to stop a page from making noise the moment it loads, not one aimed at hardware detection in particular, but it still means the check has to sit behind a click like every other piece of audio on this page. Press the button and this page creates that context and reads what the destination reports. That number is not a live poll of the receiver sitting under your television; it is a snapshot of how the operating system currently has the default output device configured.

What "channels reported" actually means

The figure this tool reads describes the current OS output configuration, not the hardware plugged into the wall. On Windows, it comes from whatever format the default playback device is set to under Sound settings, in that device's own Properties and its Advanced tab (or "Configure Speakers" on older builds); on a Mac, it is whatever Audio MIDI Setup has the format set to for that device. A 5.1 receiver connected over HDMI or optical, correctly wired and powered on, will very often still be reported as two channels until someone opens that panel once and tells the operating system there is more than a stereo pair on the other end. So a "2 channels" result from this page is at least as likely to mean nobody has told the OS about the receiver yet as it is to mean there really is nothing but stereo attached.

The override, and what it costs the result

Because that under-reporting is common, refusing to run below the layout's channel count would lock out plenty of people whose 5.1 or 7.1 is genuinely there and simply unconfigured at the OS level. "Play anyway" runs the walkthrough regardless of what the browser reported. What it cannot do is change what happens at the operating system's own mixer: if a six- or eight-channel buffer is quietly being folded down to two channels before it leaves the computer, a "rear left" step will still come out of a front speaker, sound completely normal, and prove nothing about the rear speaker at all. The note on screen keeps saying the result cannot be verified from here for as long as the override is in effect, on purpose. A step that seems to play from the wrong place under an override is not evidence of a wiring fault — it is evidence that the output still needs configuring — and the difference matters enough that the page will not let that caveat quietly disappear once you have clicked past it.

Why the subwoofer step sounds different

Every step in the walkthrough plays the same default tone except the one addressed to the LFE channel, which drops to a 40 Hz tone instead. That is not a stylistic choice: an AV receiver low-passes whatever arrives on its LFE input, typically somewhere around 80 to 120 Hz, because that channel exists to carry bass and nothing else. Send the usual tone into it and a subwoofer that is wired correctly and working perfectly would reproduce nothing, and the silence would look identical to a dead channel. The low tone this step uses is inside the range the LFE input is actually built to pass, so silence there means something has gone wrong rather than being the expected result of the wrong test. That ".1" is narrower than most people assume — not a subwoofer channel so much as a band-limited effects channel a subwoofer happens to be the usual destination for — and channel layouts explained covers what 5.1, 7.1 and Atmos each actually mean and why their channel orders don't always agree with each other.

7.1's last two speakers are a guess your receiver is making

The Web Audio specification defines a fixed channel order for mono, stereo, quad and 5.1 — index 0 is always front left, index 3 is always LFE, and so on, the same way on every browser and every device. It defines nothing above six channels. Ask for eight and the browser passes the buffer through as discrete: it hands over eight numbered channels and steps back, leaving your receiver to decide on its own what indexes 6 and 7 are for. Some receivers route them to the rear pair; others route them to a side pair instead, and reserve a separate pair of inputs for rear. There is no routing this page can apply to settle that, because there is no standard behind it to follow, which is why choosing 7.1 above puts that caveat directly into the note on screen rather than only mentioning it down here.

What this walkthrough proves, and what it does not

A step that plays from where it says it will tells you the signal path — from this tab, through the operating system's mixer, down the cable, into that one speaker — is intact for that channel. That is genuinely useful, and it is most of what "is my surround system wired up correctly" is really asking. What it cannot do is tell a receiver with its speaker assignments set wrong apart from a pair of speaker cables that are actually crossed behind the rack: both produce the exact same symptom here, sound arriving from the wrong place, and only opening the receiver's own setup menu or tracing the cable by hand will tell you which one it is. It also cannot measure level, measure distortion, or confirm that a speaker is the size your receiver assumes it is when it applies bass management — those need the receiver's own room calibration routine, not a browser tab with no microphone and no reference to compare against.

Not sure where the problem is? Run the full sound check: six quick questions, and one summary that points you at the right tool.