Can't get 5.1 to soundbar, even though EDID supports it

[suffusion]

Our normal TV setup is an ASUS Vivo Mini running Windows 10 (Intel HD Graphics 630) -> Insignia TV -> Sonos Beam. I noticed the BEAM was just getting PCM 2.0 and after some investigating determined that the TV can't pass through 5.1. So I got an audio extractor that passes sound to the Beam using SPDIF, which maybe works but maybe doesn't.

The problem is that the computer is still just outputting 2.0. CRU can't read the Extension Block on the Intel, but Monitor Asset Manager assures me that the EDID being read supports LPCM 2-Channel and AC-3 6 Channel. Speaker allocation is still 2. I spent some time monkeying with CRU and couldn't get anything to work, which I assume is me just not understanding things.

I plugged my laptop into the the splitter nightmare of cords, which has an Nvidia GPU (Geforce GTX 1660 Ti, if that matters) and so uses Nvidia HD Audio for the display. CRU can read the extension block, and sure enough the promised audio formats exist and the speaker setup is 2. So I edit the setup to 5.1. This doesn't seem to do anything at all, and nothing I've tried seems to get surround sound out of this.

I'd understand if I weren't getting surround out of the beam because the signal from the splitter wasn't HDMI-ARC (which it should be), but surround isn't even going to it. I'd love for the Vivo setup to work with surround, but I'd settle for some computer, somewhere, putting out a surround signal. Any tips on what I might be doing wrong?

[ToastyX]

You need to set the LPCM audio format to 6 channels for 5.1. Speaker allocation/setup data block doesn't affect anything.

[suffusion]

(06-12-2022 04:43 AM)ToastyX Wrote:  You need to set the LPCM audio format to 6 channels for 5.1. Speaker allocation/setup data block doesn't affect anything.

Thanks! Setup still isn't working properly of course, but at least I've figured out how to get the computer to think about putting out 5.1. Appreciate the fast response, too!