I just got my X1 last night and am super stoked about it thus far. I've noticed that the audio volume going through my receiver is very low with TV and all other audio coming from the Xbox. My system and components are as follows:
1) Denon AVR2113CI Receiver
2) Sony TV - Remote Code T2470
3) DirecTV Genie - Remote Code S1377
Right now to get a "reasonable" volume from the XBOX my receiver has to be in volume range 50-60 out of 100 when previous to the X1 the 50-60 range was very loud. I've tried tinkering with all of the X1 settings but have yet to find a way to get the audio back to normal.