Speaker Hum

Sounds like a ground issue. Get the circuit  tester and make sure the plugs are grounded and wired right. Have an electrical  guy check the grounds in the main box make sure yhey are not loose or do that your self. Check the breaker grounds on the circuits  you are using as well as the ground make sure the box is bonded to the waterpipe and the gas line

 Regards

I had the same issue - try a humx - that worked for me. 

play some tunes, and unplug the HDMI cable to your tv from cable box.

this was my problem. when critical jamming, i unplug the HDMI cable. as quiet as a nun double clicking the mouse checking email.

 also I bought some Belden better shielded cable for amp to preamp, worked also !

Belden cables shielded better than the qudioquest topaz cables, have another pair, forget the name, great stuff, but the bolden shielded the radio tower, as i had high pitched radio chatter from my tweeters, 

try cables, and TRYT unplugging that darn HDMI cable.

DO they make a better shielded hdmi cable for this , or am i just doomed to unplug when listening?

im in the boat with you, .....lets share the oar .....we will figure this out, there are some very sharp people iim here. They have helped me for quite a many years.

im keeping an eye on this one...........

Yes thanks - all RCA cables connecting the audio. The speakers have 3 prongs in the socket. They do still play with the subs unplugged. I'm going to run through these tests. I just can't unplug the cable coax at the moment because all of the house feeds off this cable box so I'll start a riot. When I can I will run the tests and report what I find. 

Also when I moved in I had every outlet in the house with new GFIs - would the electrician have noticed if the box /  grounding in the house was off or not necessarily?

Yes agreed thanks many much smarter than I hence the SOS!