Help With Descent Sub

MartinLogan Audio Owners Forum

Help Support MartinLogan Audio Owners Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

MDSPHOTO

Well-known member
Joined
Jul 6, 2008
Messages
222
Reaction score
1
Location
Atlanta
When I came home today I heard a weird low rumble in the house when I approached the subwoofer that low rumble turned into a loud roar. I quickly unplugged the whole system and powered it up again with the same result. Can anyone provide any advice as to what might be going on with the sub?
 
Hola. First of all, you have to find from where it is coming the rumble. Disconnect the input cable to the woofer, and turn it on. If you have the rumble, then it is the power amplifier of the sub. If the noise is gone, them you might have a ground loop. You have to track from where this ground loop is coming. You never know when you are going to have a ground loop problem. Usually the tv antenna is the culprit. Happy listening.
 
Thanks. When i unplug the cable to the woofer the noise stops and will not make any noise for a day or two, but when plugged back in then the hum starts again. All of the equipment in the rack and subwoofer is plugged into a power conditioner which is plugged into a dedicated 20 amp circuit. The TV, center channel and front speakers are plugged into a separate power conditioner in a non-dedicated outlet. I plugged the sub into the same conditioner as the TV & front speakers which stopped the hum for about 2-weeks and then last night it started again. This is driving me and my wife crazy because the hum usually starts at 3 or 4 in the morning. Any other ideas for trying fix this problem?
 
Hola. You are not reading my advise. The problem is a ground loop. It is intermittent. To track from where the problem is coming, first, unplug the cable antenna from your cable box, or from the tv, if you have it plugged there. If the hum goes away, then you just found the culprit. To solve this problem, you have to get an antenna ground loop suppressor. Usually, Radio Shack has it. If the problem persists, then reverse the polarity of the sub at the AC mains, or use a cheater plug. You can get it at any hardware store. Happy listening.
 
I tried your "advise" and still have a hum. Will need to call ML to see if they can offer a solution.
 

Latest posts

Back
Top