Subwoofer Hum


A friend of mine has the same Martin Logan Dynamo 700 subwoofer that I do.  His has had a hum issue for quite a while and he finally sent it home with me yesterday so that I could mess around with it.  I plugged it into the outlet and turned it on, no hum.  I connected the cable from my subwoofer to it, no hum.  I turned the volume up all the way and shook the house for a bit and it seems to function perfectly.

The only thing that I can think of is that his super cheap "linguine" cable was causing the issue, but didn't want to go spend the time or effort to hook his cable to my home theater receiver, so I just passed it back with a loaner BJC LC-1 cable that's the same kind that I'm using.  If that doesn't work, then I'm thinking that it has to be something unique to his house/setup.

Is it possible for a subwoofer cable to be so pathetic that a hum can be created from proximity with its own power cable?

mceljo

Probably nothing to do with cabeling.. His system is picking up offset, possibly from cable TV.

It just seems like the sub, likely his only speaker with strong 60 Hz output.

In my system hum is usually cable related, usually due to the contact between the cable and the preamp or the preamp section of an AVR.  Cheap cables are usually the culprit so best not to use any

Hello,

  The ground is picking up a stray voltage and back feeding it into the sub-woofer.

. If the humming should come back, pick up a three prong to two prong electrical adaptor and that should do the trick. It's a pretty common problem

Bill