I have a separate stereo (2.0) setup connected to my TV (optical out, into stereo DAC) and most of my videos are with surround audio so I suppose the audio is transcoded & normalised to stereo?
Somehow, when watching through the Plex app on my Chromecast with Android TV, the volume is significantly lower when compared to Kodi on the same device or Plex installed natively on my LG TV or Xbox Series S. In all cases I’m watching the original files, since I’m on my local network. Unfortunately my TV is to slow to play some of my source videos and the Xbox can’t be controlled with the TV- or Chromecast remote.
In the settings of the Android TV app, I’ve enabled volume leveling & Audio boost is set to “Huge”, which don’t seem to make a difference. I’ve also tried changing the Audio passthrough setting, with no luck, but I think that was to be expected since the audio output comes from the TV, not the Android dongle itself. In the Android TV audio settings, I’ve tried setting the formats to “None: never use surround sound” or “Manual” & deselected every format.
By the way, the settings menu on the Android TV version of Plex, with the round icons… what kind of sick joke is this? 
Even the outdated LG TV app has a nicer settings menu, just a normal clear list, just like on the Xbox.
