# Solved: Subwoofer hum



## Psycher (Oct 18, 2007)

Intense buzz when I first plugged it in seemed like my $13 purchase at goodwill was a waste. But after fiddling with it a bit, I learned that it wasn't in fact constant. It changes depending on what's plugged in, and the position of the wires/cables.

Things to note: hums a good deal with NOTHING plugged in. Oddly enough, plugging the main cable in helps a good deal, but only when positioned slightly.
Also has a 4xSpeaker Wire In + Out. These do not appear to function, but having speakers plugged in anyway also seems to give some control over the hum.

This is too similar to how a radio's antenna's get finicky in different locations, and if your hand is near. Even so, I don't know a way around it. Is there any simple fix (shielding tips, etc) that could get rid of the hum entirely?

Also, unrelated, those speaker wires in, I've never seen them before going IN to a unit. And they don't seem to work. I cut off the ear pieces to some cheap headphones to get two sets of + and - cables, then plugged them in. No luck. This seems extreme though, am I missing something?


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## Drabdr (Nov 26, 2007)

Hello Psycher!

If you get a chance, maybe a pic of the back of the subwoofer might help. 

I too have noticed my subwoofer making noise once in a while. Are you running a shielded cable from the sub to the receiver? Is the "signal" cable running parallel with the power cable?


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## Psycher (Oct 18, 2007)

Sony sa-w303, manual says nothing about dealing with this level of buzz. But I have it mostly figured out, mainly due to experimentation and tape. Still there, but not a dealbreaker as I only use it when at volume.

Still, general shielding tips would be nice. And the power and main signal cable are going opposite directions. The majority of buzz seems to come from anything immediately next to the back of the receiver. After the first few inches, adjusting the cables doesn't seem to make as much of a difference.

Still, very curious over the function of those two sets of "+,-" cable 'in' ports. If I can get those to work I can Frankenstein myself a 4.1 surround system.


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## Drabdr (Nov 26, 2007)

I didn't get to dig too much into the instruction manual. But what I'm guessing those inputs/outputs are for, is to provide a "crossover" for the other speakers. There is a bridge in the subwoofer to segment to specific speakers the appropriate frequency. 

If you are using speakers other than the ones that came with the sub-woofer, assure that the speakers you are using will work at the designated frequencies of the connections. Otherwise, you may "lose" sound at limited frequency ranges. 

Is there a frequency range listed on the connections of the subwoofer?


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## Psycher (Oct 18, 2007)

It's got a range adjuster.

Have everything figured out, turns out those 4 in's are an alternate input that only work if the main input is not used.
Also, they only work if the signal going in is powered. An unpowered signal, IE from a computer, will be too quiet for the sub. That section is a 'man in the middle' of what would otherwise be a strait signal line from another receiver to it's own set of speakers. Thereby proving itself useless to my quest for surround sound (besides that I now have a subwoofer).

Thanks anyway.


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