Roku 4 (Ultra/Premiere+) - Atmos/DTS 7.1 downmixed to AAC stereo, not AC3 5.1 with Sonos [SOLVED]

[mattdmeyer]

I found another recent thread that has the same issue.

Can I force Roku Plex App Transcoding TrueHD 7.1 to DTS 5.1 instead of AAC Stereo?

Here’s one example that to me makes no sense. Audio is EAC3 5.1 get my Plex Server is transcoding it to AC3 Stereo. Why wouldn’t it transcode it to AC3 5.1. Then I thought about the Roku settings Audio being set to Dolby Digital, DTS. So I switched it back to Auto thinking that it would then allow Dolby Digital Plus to play if it was available. But nope, still transcoding EAC3 5.1 to AC3 Stereo. [Screenshot_20200724-113435_Plex Dash] And here are the logs for it: Jul 24, 2020 11:37:41.621 [2…