Hiss, hum bad for speakers?

I have two Rel Stentors. One older model and one newer. When I hooked up the second one recently I had a bad hum problem that I didnt have in the other one. It turned out to be a ground loop problem. I recommend eliminating the chance of it being a ground loop.

I dont know what makes the newer models more seceptable to the hum but the high current cable is a little different in the newer models.

I would say you have a ground loop somewhere. I use 2 Stadiums, no hum at all. All on one curcuit. One time while changing speaker cables, there was a very noticable hum from one of the Stadiums. The ground wire was not connected yet and i forgot to unpower the subs while connecting the new cable. The amp and pre was off of course but the REL was on. After unpowering the sub and connecting the cables and powering up the system, back to normal, no hum. This told me a ground loop caused the hum. I would ck that all connections are secure and in order first. Maybe redue the connections from amp to REL and be sure no loose strands of wire are free. Ck your internal house line connected to the REL for a possible ground problem. Maybe connect the setup to a completly different curcuit to eliminate any possible ground problem in the curcuit. Disconnect one component at a time to isolate the culprit and see if the hum ceases. Hum is usally a ground loop or transformer interferring like mentioned above from others. Call REL and explain the problem, they should be able to help. I think you can call Sumiko in CA, Sumiko is the US distributor for REL. The hum you describe is not normal and should be eliminated. Good Luck!!

Dont forget to check your cable tv for the ground loop also.

I will redo all the connections this weekend and report back. Thanks.

Okay, after pulling out all the cables (and my hair) and redoing them, I have a theory. First, the hum has noticably decreased after reorganizing the wires. This led to an extensive removal and plugging in over every single cable, starting with the setup in straight 2ch audio and then growing the entire home theater around it. What I noticed was that that hum is always present, just quieter. The more connections I add, the louder it gets, until it is just barely audible from the listening position. Then, just out of curiousity, I changed the preamp setting from 2ch direct to dolby pro-logic. Walla, part of the high ringing (the annoying part) dissappeared. Now here is the disturbing part. I do not think that the pre-amp is truly "causing" the ring/hiss/hum. I think that during 2ch mode it is just so sensitive that it is picking up the darned video noise (it still broadcasts that stupid gray screen to the TV even in 2ch direct mode). Madrigal will be getting some irate-customer-email shortly, however, I don't think this is a fixable problem. The unit works fine. It just picks up the extra noise in the system. The unit is quieter during DVD movies, but if I pause the DVD I can actually hear the electonic cycling going on in the DVD player through the speakers until I hit play again. In all honesty, I am talking about a barely discernable noise that I cannot hear during music or movie listening. But after going from my 2ch only system where even the slightest noise was like a 3 alarm fire I guess I am a little picky. Thanks all for the advice.