Just wondering if you were able to get any concrete answers on this. I am seeking the same kind of info. Except I need/want the audio to pass though not transcoded and in AC3 format (7.1 surround sound with LFE). My Xbox One has two settings - 7.1 or Bitstream. I take Bitstream to be like pass though. Anyway, on my Xbox One playing video via DLNA from my PMS, the audio is louder and clearer than when playing the same video though RasPlex. Both seem to play the audio channels discretely. The Xbox One just sounds better. I was looking for a similar Bitstream setting in RasPlex and could only find what you have found as well - check mark boxes for AC3 and DTS Enabled AVR. I too am wondering if Rasplex is manipulating/transcoding.
Thanks.
