For my home theater setup, I have a HTPC next to an older Denon 5.1 receiver.
I use a Logitech K400 wireless keyboard to control my HTPC. Anytime I use a browser (to watch netflix), I get really annoying audio interruption through my speakers and through my headphones. It's a high pitched, slightly crackling noise. It gets worse when I use the trackpad from the keyboard. Even if I switch off my keyboard, the sound is still there. It doesn't matter if I plug my headphones into the HTPC or the receiver, I get the same noise. When I plug in a normal USB keyboard, unplug the wireless usb stick, the sound goes away. I have two of the same logitech woreless keyboards (I have two HTPCs), but both of them get the same interference.
So, obviously, there is something interfering with my wireless. Any ideas what it could be? Any ways to prevent this problem? Thanks!