Test every speaker in your surround setup.

Almost always a downmix. If your operating system's output is set to "Stereo", or the movie's audio track is stereo, everything is folded into the two front speakers no matter how many are connected. Set the OS output to your surround device (and configure it for 5.1/7.1), then make sure the source is sending a multichannel track. Browsers in particular often downmix, which is why this test switches to real per-channel routing only when the OS reports six or more output channels.

Partly. A soundbar usually presents itself to the OS as a stereo or a virtual-surround device, so the browser sees two channels and this test runs in virtual mode. That still confirms the bar makes sound and that left/right/centre placement works, but it can't verify discrete rear speakers the bar simulates through beam-forming or wireless satellites. For true discrete testing you need a system the OS exposes as a genuine multichannel output.

Web Audio can only send as many channels as your selected output device reports. If that device is set to stereo — or is inherently stereo, like most laptops, headphones, and Bluetooth — the maximum is two channels and real surround is impossible. Switch the system output to a receiver or sound card configured for 5.1/7.1, then reload. The facts panel shows the maximum channel count it detected so you can confirm what's available.

Optical (TOSLINK/S/PDIF) has limited bandwidth: it carries compressed 5.1 (Dolby Digital, DTS) but not full uncompressed 5.1/7.1 or object formats like Atmos. HDMI has far more bandwidth and carries uncompressed multichannel PCM, lossless formats, and Atmos. For anything beyond compressed 5.1 — and for the cleanest signal — use HDMI between the source, receiver, and display.

The centre carries most dialogue, and several things can suppress it: a low centre-trim level in the receiver, an aggressive "dialogue normalisation" or "night" mode, or a speaker layout that doesn't list a centre. Raise the centre level in the receiver's channel trims, disable night/compression modes, and confirm your speaker configuration includes a centre. If the centre node here plays clearly but films still bury dialogue, it's a receiver setting, not the speaker.

That means your speakers and channel routing are fine, and the problem is the source. Check that you selected a 5.1 or 7.1 audio track (many discs and streams default to stereo), and set your player to bitstream/passthrough so the receiver decodes the surround format rather than the player downmixing it. Streaming apps also gate surround behind higher tiers and specific devices — verify the title actually offers a surround track.

The LFE is a dedicated low-frequency effects channel — the ".1" in 5.1 — carrying deep bass like explosions and rumble, roughly 20–120 Hz, to a subwoofer. You don't strictly need a sub: with bass management, that content can be redirected to full-range front speakers set to "large". But small speakers can't reproduce it cleanly, so a subwoofer is strongly recommended. The LFE node here plays a 40 Hz tone — you'll feel it as much as hear it.

It depends on your room. 7.1 adds two rear speakers behind the seating, which improves the sense of envelopment in larger rooms where the side surrounds can't also cover the back. In a small or medium room with seating near the back wall, 5.1 often sounds nearly identical because there isn't space to separate surround and rear. If you're chasing immersion in a bigger room, height-based Atmos usually adds more than extra ear-level channels.