I have a Sonos ARC which I understand was recently updated to play DTS. My TV is a Vizio PX75-G1 with ARC, not eARC, where Sonos is connected. On Blu Ray and 4k Blu Ray discs the Sonos downgrades to stereo no matter what I try (including setting to TV to Auto, PCM, Bitstream, Dolby Digital). My player is Oppo with audio output set to Auto.
Best answer by GuitarSuperstarView original