Start with the operating-system test
Select your surround-capable HDMI, USB, or audio-interface output and configure it for 5.1 where that option exists. Use the operating system or receiver’s own channel test first. If that test cannot isolate all six speakers, fix that path before comparing the browser.
Check what the browser exposes
Open the surround sound test and select Check output support. The reported number is the Web Audio destination’s maximum channel count. It describes the browser’s current output capability; it does not count your connected speakers or verify the receiver’s settings.
If the result is two channels
Confirm the correct system output is selected and configured for surround. A Bluetooth route or a stereo device may expose only two channels. Reload the page after changing the output so the browser creates a fresh audio context. If the browser still exposes fewer than six channels, use the system channel test for physical 5.1 and treat the website’s stereo preview only as a labeled demonstration.
Use a direct receiver mode when checking routing
Virtual surround and upmixing can send a single source channel to several speakers. For a routing check, choose a mode that preserves incoming multichannel PCM, when supported by your equipment. Follow the equipment’s documentation rather than changing an unfamiliar format at random. This test generates browser audio; it does not transmit Dolby or DTS encoded bitstreams.
Confirm each speaker by listening
In Discrete 5.1 mode, test front left, front right, center, LFE, surround left, and surround right individually. The intended Web Audio order is L, R, C, LFE, SL, SR. Note the actual speaker you hear. If a channel appears in the wrong place or multiple speakers, compare system channel mapping and receiver processing.
Understand bass management
A subwoofer may reproduce bass redirected from other channels as well as LFE. Conversely, an LFE signal can be rerouted by your system. Do not treat any subwoofer sound as proof of correct LFE isolation. The tool’s 65 Hz LFE tone is a basic channel cue, not a crossover or level calibration.
What this does not test
The tool checks a six-channel 5.1 layout. It does not validate 7.1 routing, Dolby Atmos objects, listening distance, delay calibration, room correction, phase alignment, or calibrated speaker levels. A sound-level meter, measurement microphone, or your equipment’s calibration procedure is needed for those tasks.
Technical references
The implementation follows the W3C Web Audio channel-ordering model and reads AudioDestinationNode.maxChannelCount to gate discrete mode.