Solved! audio from TV and PC to one 5.1 system

[benitobeybi]

I want to use my Sony HT-RT3 5.1 system (Dolby only) for my TV and PC.

I have been using my Samsung UHD TV as my computer monitor via the PC's GPU hdmi for both display and basic audio. I, of course, get stereo sound from my TV speakers. The TV is connected to the mentioned surround speakers via HDMI ARC, and it's working perfectly for streaming and USB sources.

I want to use my PC mobo's audio ports to connect to the Sony speakers as well. But the PC only detects them as 2 channels via optical cable. So I bought a bi-directional 1 x 2 hdmi splitter so I can connect both the PC and the TV (both HDMI) to the speakers' one HDMI ARC port. I did not get audio from either sources. The TV is still connected to the PC as a display via GPU HDMI at this point and display wasn't a problem.
I switched the TV's audio out to something else so it won't send sound to the 5.1 sound system as I was switched to the mobo as the PC's audio playback and vice versa. No cigar.
Also I connected the speakers directly to the mobo hdmi out and it only detected them as 2 channels. I have refreshed my drivers and tried to tweak using utilities but I could not find a fix. Options to configure to 5.1 aren't available.

Any help with this? I googled around and saw a fix by turning on each component one by one, sort of a handshake issue, but it did not work for me. Do I have to use an HDMI hub that's specific for audio extraction? Do I need a more sophisticated receiver so my pc would detect beyond 2 channels via HDMI? I understand that the HT-RT3 is pretty basic.

More details:

TV: Samsung 49NU7300
Receiver/Speakers: Sony HT-RT3
Mobo: MSi MPG Z390 Gaming Pro Carbon AC (supports 7.1 surround)
GPU: ROG Strix RTX 2080ti Gaming OC
Audio driver: Realtek

Cheers

 

[americanaudiophile]

Since your TV is sending out 5.1 via HDMI-ARC for other sources so the TV should already be set for bitstream output in the audio menu.
If you can't get the PC to output in 5.1 via HDMI or optical then the problem may be in the mobo or mobo audio driver. Check for updates if you haven't.
You should be able to use an HDMI input selector with audio extraction. These usually have a switch to select 2.0 or 5.1 via optical output.