Hi All,

I've installed my new Arc Ultra but I was receiving only stereo PCM.

Reading on the internet I found to disable Dolby Atmos on my LG tv etc and use passthrough on my HDMI Arc interface but nothing seemed to work.

Contacted Sonos and investigated the issue for quite some time also got higher support involved. End conclusion was to contact LG as it seems that the HDMI Arc interface only seem to support Stereo PCM.

As I only have HDMI Arc and not eArc I thought that could have been the problem?

To fix this I thought I buy a hdmi to optical connector so I could at least try the optical connection dolby digitial and not dolby atmos.

Finally I found the problem: It was the setting on the ZIGGO Media box next, it was set to stereo.

I should have tried my chromecast or ip connection on the tv that would have also turned out the issue was not the tv but the Media box. 

Maybe a bit stupid after all but just wanted to share this, in case someone else is also struggling