I've tried with the Switch today, and there are issues with the menu audio when using eARC (I didn't try connecting the Switch directly to the soundbar). I don't hear clicks when I move between items. Also confirmed that Surround audio does not work, only Stereo. So, my combination of Q80T and this soundbar definitely does not support multichannel PCM over eARC right now.
Edit: Also tested with the Switch to the soundbar HDMI In, and same behavior with the menu sounds, but multichannel works properly.
Here's a summary of what seems to work so far:
1. I can get DD, DD+, TrueHD, TrueHD with Atmos all to work properly via eARC. There seems to be a quirk with my Radeon card where it will not send TrueHD to the TV unless I override the EDID to say that the TV has 8 speakers. I cannot get any DTS streams to work over eARC (maybe a limitation of the Q80T TV?)
2. I cannot get multichannel PCM to work via eARC (unclear if this is the Q80T TV or soundbar's issue). Even if I override the EDID, only the front left and front right channels will produce audio when sending multichannel PCM. Multichannel PCM does work properly if connecting directly to the soundbar's HDMI input. From my understanding the LG C9 and CX have the same issue, with a fix in the works.
Last edited by voyager6868; 06-11-2020 at 03:42 PM.