Speaker Hiss and Power Supply Buzz Since Moving

Hi y'all.

Since I moved into a new house my Yamaha HS 8 speakers emit a constant hiss from the tweeter and a rumble from the bigger cone as soon as powered on even if no audio device is connected, and my power supply buzzes as soon as powered on even if disconnected from everything.

I've tested other outlets in the house with and without a power strip/surge protector and the problem persists. I tested them at a friend's house and the problem stopped.

I've test my outlets for ground and they're grounded properly. I also got a cable tv ground loop isolator and that didn't help.

Any recs would be very much appreciated :love: