Sub-woofer is making a horrible noise when no media is playing?

Question

I have never had any problems with this subwoofer before. I recently moved houses and setup my system there. Everything seemed to be working beautifully until I woke up in the middle of the night to horrible feedback coming from the subwoofer. I immediately turned the power off and it stopped. So, I tried to switch the subwoofer to "Auto" mode which kind of puts the speaker in a sleep mode until it is being used. This also did not solve the problem. When music is played on subwoofer, it sounds great, but once it ends, after a while, a feedback "beat" is heard and repeated over and over. Any suggestions? This wasn't happening before the move.

Answer 1

Hmmm, it could be many things... I have a JBL speaker system with a powered sub and I had a similar type of feedback humm, but I discovered it had to do with the auto sleep mode. Oddly enough (like you) this only happened to me after moving into a new home, go figure! So aside from some trial and error with the power save feature of the subwoofer, it's time to dig deeper.

Do you get normal results when you run a test-tone test, if your head unit has this feature? First, if you don't own a second one, see if you can borrow another subwoofer and swap it out temporarily. Try to rule out an issue with the speaker itself, if another sub does the same, you have an issue with your head unit or cabling or power. Are you using a halfway decent power distribution system or power strip, like a monster power strip with good noise filtering? In the new house, where you set up your system, are there any sources of interference nearby like from utilities or appliances or computers? Are you using a good quality cable to conect the sub to the head unit? I realize it worked fine before, but it could be a cabling issue if there's an external electromagnetic interference problem near the new home that didn't exist at the old home, like from nearby communications equipment, alarm systems, wireless networks, cordless phones, baby monitors, wireless CCTV systems, etc.

Or it could be dirty power for these same types of reasons, so be sure to use a good power strip/filter. Expect to spend a few hundred dollars on a good one. Myself, I use the Monster Power HTS 3600. And make sure the outlets where you have everything plugged in is properly grounded. Use a tester or have someone who knows home electrical confirm it for you. Ideally, this will also be a dedicated 15 or 20 amp outlet with nothing else on it like lighting, etc.

Answer 2

Check the cable between your subwoofer and receiver for proper connection and inspect the wire for damage. This kind of sound could be a grounding problem too. A better description of the sound you are hearing could help determine the problem more precisely. Sometimes it could be caused by an electrical problem too.

Answer 3

theres probably wires touching each other that alway makes noise like that just reconect everey thing make shure all the wires are re-striped and put them in clean.