Thank you again. I now have the other pair on the Z9, and it sounds awesome. I have always had a hum in one of my subwoofers, so I unplugged the Monster cable going to that sub and bought a 35 ft blue jean LC-1, and the hum almost went completely away. I did have a break in that Monster run, I had to use a coupler because the Monster wasn't long enough. However removing the coupler and running a 35 foot cable did not solve the issue entirely. I talked to Jeff at blue jeans, and he said I did not have a ground loop, because the hum wouldn't have gotten louder when I turned up the volume on the sub. At any rate, the moral of the story is, sense I removed the main preout split, the hum has vanished. I tried everything and that hum would not go away, I even unplugged all of my audio stuff , and that hum was still there . Jeff said there had to be some kind of interference coming into that cable, so I tried one more thing, unplugging my Z9 power cord from the Monster HTPS7000, when unplugged ( hum went down significantly,) but still there. Now that the y splitters are removed the hum is gone.
