Low Hum in Subwoofer Output

Hi gang,

I have a 950 Pre/Pro that I love dearly.

I use my 950 to drive a Crown K1 amp and two SVS CS-Ultra subwoofers.

Recently, I developed an unexplained low level hum in my subs. I can see the low signal present on the display of the Crown amp, as well as hear it if I am close to the subs.

After suspecting cables, and all the normal stuff I was stumped. You see my room is a professionally designed HT and as such all the power is on the same phase and leg, so I should not have power hum/ground loop type problems.

Anyhow after almost pulling my hair out, I found this thread in the 950 archives here:
Low Level Hum in 950 Sub Output

I tried disconnecting my Cable input, and voila the hum completely disappeared.

I'm now going to get the Xantech 63400 Ground Breaker, as suggested in that thread.

Xantech 63400 Ground Breaker

I'll post back, but I suspect this will fix my hum problems.

Thought someone else may run across this problem in the near future!!

Take care,

-- Cain

PS Looking back I should have suspected this. I only recently added Cable down in the theater, and I should have realized it was the only thing coming in there with the potential to create hum.

The axact same thing happened to me. It ws the final straw in switching back to DIRECTV. The Scientific Atlanta Cable box produced the hum (which i defeated by using the "cheater" adapter) but my satellite receivers never did

I look forward to hearing how your ground breaker works out. Thanks for the information.

i got some hum from my powered center channel the other week and it turned out to be a slightly loose connector jacket on the rca input to the speaker. well either that or a bad fit onto the rca jack... either way, i twisted it a little and the hum stopped completely. stupid m1000 monster cable!

Well, this looks like it was even easier to fix than I thought it would be.

I already had a Monster Cable Power strip down there, and it has a Cable/Sat Coax in and out.

I connected the tv cable to that, and bingo!! no more hum, at all.

I'm gonna experiment, I think I would rather put that in the attic ahead of my signal boosters, to be certain I do not degrade my signal any.

I'll let you know, I have not rechecked my signal, but I suspect it is fine now.

-- Cain

Cain.
Curiously I have found out after a long time bitching about my cable reception on some channels, it was my Power Bar at fault. I previously had my cable connected to the in and out of the bar. When I moved the cable connection directly to the TV my reception improved a lot.
So I would be interested if your Monster Power Bar is not affecting your cable reception.

Monster power products have Ground Loop Isolators (Ground Breakers) built into their highend powerstrips and power centers.