I've taken great care to make sure my power cables do not occupy the same space or touch or cross my other cables but the remainder of my cables run parallel as needed.
All are above the floor/not in wall and are exposed.
Should I be concerned about coax/speaker cable/sub cable/ cat5 cables crossing, touching etc?
The only noise/hum in my system comes from the PVR. Its about to be replaced.
1/2 the income and a 3rd child has a funny way of sapping your personal (HT) time...

Life is good.