Some of us have been discussing this topic in another thread
https://forums.plex.tv/t/plex-sonos-and-hi-res-music-content-24bit-32bit-48khz-88-2khz-176-4khz-192khz/
It would appear that the Plex default Sonos profile is set up to transcode everything above 16/48 to aac (unclear what bitrate). I’ve been trying to figure out if it’s possible to override the profile to allow direct play of everything up to 24/48 and transcode everything above that limit to a lossless codec without upsampling. So far I’m stuck, so any input is appreciated.
Currently, the only way that I’m aware of to directly play 24/44.1 or 24/48 content is through the Sonos library. AirPlay to Sonos from Plex on an iOS device (which can direct play content as high as 24/192 in my testing) is possible but I am not certain of the exact bit depth/sample rate Airplay uses to accomplish this (maybe and hopefully max 24/48 without upsampling).