Yep again what player your using reacts differently"Make sure both settings on every connection is set to bitstream not auto"
I have a 7.2.2 setup, and I find that with my Oppo UDP-205 if I have the output set to bitstream, my Pioneer Elite SC-95 decodes it as DTS-MASTER Audio and sends a signal to the surround back speakers if I'm using the "Auto" surround feature on the AVR. In that case, I have to go into the AVR settings and turn my surround back speakers to "off" if I want a true quad experience. If I have the OPPO send a PCM signal, my receiver only plays those 4 elements (FL/FR/RL/RR) and doesn't create the surround back signal on it's own.
Oppo vs Sony vs Pioneer
Settings n AVR hookup matters
Find thread re Sony x800