along with achilles says, on the xbox when connected to atmos avr is always ATMOS/PCM out over hdmi.
all audio is converted to atmos/pcm (even if originally stereo or whatever)
NO audio is passed through, except a bluray played directly in the xbox bluray app.
so, it LOOKS like xbox supports atmos, but we never actually get the original, unmodified, truehd+atmos that a bluray rip uses.
the only way to get full 4k/hdr+HD audio is nvidia shield, or perhaps a properly configured HTPC.
Please read the whole thread @ Plex, 4k, transcoding, and you
