I built an HTPC with the new coffee lake and z370 platform to enjoy streaming services in UHD with HDR. However, I've run into a problem that I haven't been able to solve.
When I connect my HTPC to my receiver through HDMI, I get noise in my subwoofer channel. The noise is worst when there is movement on screen, whether scrolling down a page, watching an animated gif, or playing a video. When the screen is static, it is mostly silent, with only the occasional burst of bass noise. After trying different HDMI cables, changing inputs on my receiver (and even a different output from the receiver), disabling all other onboard devices (LAN connections, realtek audio, etc.), and swapping the power supply, I couldn't get rid of the noise. If I connect a Roku device with the same cables, there is no noise. Only with the HTPC.
I then connected the HTPC directly into the TV and ran an optical cable from the TV to the receiver. That fixed the subwoofer noise issue but introduced a couple new ones: (1) now my only options in the sound settings are "stereo" and "dolby atmos for home theater" whereas before I could choose from a whole suite of options (quadrophonic, 3.1, 5.1, 7.1, etc.); and (2) since my receiver is now only connected to my tv through an optical cable, it can't send its OSD to my tv, meaning I can't see menus to calibrate, change settings, get visual feedback of volume levels on screen, etc.
The best solution would be to get the HDMI working with no subwoofer channel interference, because then I can use the OSD and have access to all the sound options. But at this point, I'd even be thankful for a way to get my full array of sound options in the intel audio settings so that I can set it to more than just stereo while I try to figure out the HDMI issue.
Mobo: Gigabyte Z370N Wifi
Graphics: Only UHD 630 (no PCIE card)
Audio: Only Intel (realtek onboard is disabled)
Video Driver: 18.104.22.16849
Sound Driver: 10.24.0.1
Intel Dual Band Wireless-AC 8265: 22.214.171.124