If I remember correctly, while in the app and playing media press the xbox button on your controller and there should be volume controls in the xboxs sidebar menu. I can't remember it they are in a sub-menu off of there, I'm not infront of my xbox atm.
I can give better instructions when I get home if you haven't figured it out by then, but that wont be for another 8hrs
Start playback, press the xbox button, press a on the emby app and you will get media controls and a volume slider to mix between media and what I assume is voice chat volume. (its just a music note icon vs a controller icon, not sure what the 'controller' volume is supposed to be in the context of a media app)
Edited by darkassassin07, 02 December 2019 - 03:34 AM.