Is my subwoofer dying?

[atgcpaul]

I have a Sony surround sound system. It's not high end, 4-5 years old, but
I'm not ready to replace it.

Recently I've noticed a bass "howling" coming from the sub that will fade in
and then fade out. Like feedback. I normally leave the sub on when the
system is off but the howling can happen when the receiver is off so I keep it
off until I need it. It intermittently howls now when in use.

All the connections look fine. The sub plugs into the receiver via an RCA
cable. There are a bunch of wires back there, but none of the other speaker
wires seem crossed.

The sub is on a surge, but I'm wondering if it could have taken a hit when it
was off. Or some other problem.

Help.

Thanks,
Paul

[BigguyZ]

It may be a 60hz group loop. That can happen when your system is grounded through two connections- i.e. the cable wire and a ground connector for a power cord. Google it and you should find oogles of solutions.

[LCHIEN]

Paul there's usually one signal cable going from the amplifier to the subwoofer (assuming you have an amplified subwoofer and a subwoofer output on your receiver). Unhook the cable at the subwoofer end and see if the noises go away. This will at least tell you if the signal is coming fom elsewhere or being invented within the sub.

Of course there are are many variations on subwoofers and wiring options, including those that take in the speaker signals and capture the low frequencies and reuse them.

[atgcpaul]

It may be a 60hz group loop. That can happen when your system is grounded through two connections- i.e. the cable wire and a ground connector for a power cord. Google it and you should find oogles of solutions.

Well, it's been a few months since I had my system on. Anyway, moved it to
a new location in the house with same hum resulting. Looked into the ground
loop thing last night and bought an isolator from Radio Shack today. Works
just fine now!!! Thanks for the advice. You saved me a ton of money and time.

Paul