I have recently moved house and on setting up my media pc, I noticed I was not getting any sound out of my rear speakers. A channel test on the receiver confirmed that they are working, so the issue has to be with Windows. I just upgraded it with a new SSD and case and performing a sound test on booting and installation of drivers, there is still no sound from the rear speakers. The sound that is meant to come from them is coming through the front speakers. The front (left, right and centre) speakers and subwoofer work correctly.
My pc is connected via HDMI to a Pioneer HTP-072, a HTiB (Home Theatre in a Box) comprised of a Pioneer VSX-324 with passive sub and speakers. I have never had any problem with them before. The HDMI cable is plugged into a Radeon HD 7870 with Crimson 17.11.2. Running video files on Kodi, the correct formats do appear on the receiver (TrueHD, DTS-MA, etc.) I have carefully rewired all the speakers but, as explained above, a channel test on the receiver has sound coming from the rear speakers as normal.
Any ideas? This is driving me crazy. It has to be a problem with Windows but I can't find what that might be. It was running on Windows 7, is now running on Windows 10, but the issue oddly remains.