Unable to send multichannel PCM audio from PC to LG B6


Mar 1, 2012
I recently purchased an LG B6, and came to realize my good old AVR (a Denon 1612), featuring HDMI 1.4, won't do HDR pass-through, so intending to keep the Denon, I switched to having the TV in the middle, instead of the AVR as I did until today. I have managed to get audio sent from the TV to the AVR via both ARC and optical, multichannel working fine, but the problem came when I tried to have multichannel audio from the PC to the TV.

The problem is, the PC (using a GeForce 1070) sees the TV as accepting only stereo PCM audio, and only allows to select stereo in the device's speaker setup. Needless to say, I need 5.1 PCM to get multichannel audio in PC games.
Some guy in another forum said he could send multichannel audio from a Playstation 4, so I tried using an EDID override to copy the audio capabilities from the Denon to the TV, which allowed me to have Windows think it can send the TV any of the stuff the Denon takes, but even then any audio from channels other than left front and right front is lost along the way to the AVR. My guess is that for whatever reason, the TV is decoding the stream and only letting L and R through.

On the bright side of things, multichannel pass-through does works fine for DD and DTS streams, allowing to watch a movie on the PC and have semi-decent multichannel on the AVR. Dolby TrueHD and DTS HD, though, are a no go, even using ARC (optical obviously doesn't support HD audio).

So yeah... Any ideas? Suggestions?

I'd like to think I won't be forced to buy a new AVR just to have it pass through HDR, so any help will be appreciated.


Mar 1, 2012
Well, no comments received but I'll share my findings during this struggle, which may help anyone encountering the same problem.
First of all, I found out that what I intended to do isn't possible since ARC shares the same limitations as SPDIF and therefore doesn't support multichannel PCM, or high definition audio formats.

So, AFAICT the choices in this scenario (worst to best) are:
- Have two separate cables from the PC, one to the AVR and one to the TV
- Buy an HDMI matrix switch with EDID management (and pray that it handles HDCP properly)
- Buy a new AVR



Jan 19, 2012
I'm interested in your post because it's an issue that I am going to have to deal with at some point ... my receiver also only does hdmi 1.4 pass-through.

When you you implement a solution ... would you mind posting what you did and ... how well it worked? Thanks
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