# Help me get rid of subwoofer hum?



## JJEdwards

I have an Infinity BU-2 12" powered subwoofer. It's about 10 years old.
I've been getting an unwanted low frequncy hum over the audio and can't seem to get rid of it. What causes it and how do I get rid of it? It annoyed me so much that I just unplugged the sub for now.


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## bt-rtp

A hum in audio speakers can be caused by a couple different conditions. The most typical are:


The audio wire(s) running in parallel to AC cords or AC outlet wiring in side walls or a ceiling. In this case, the audio wire is picking up what's called a 60 cycle hum.
Audio wires being placed near other sources of RFI/EMI. These include fluorescent light transformers, UPS/Battery power supplies, power strips, etc.
A hot ground could be the cause. This occurs when another electric appliance or device in the dwelling has failed and is passing electricity to the ground wire of its cord. This in turn makes all of the grounded outlets hot on their ground wire.
Dimmer knobs for lighting are fairly well known to cause audio hum.
Some people coil up AC electric cords when they are too long and leave them in a pile or all arranged together creating a type of coil, with audio cables adjacent to this coil it can be the cause of audio hum.
It's possible for an old malfunctioning GFI outlet to cause a hum as well.
Loose coax connections are known to be cause of "RF direct pickup", make sure everything is finger tight plus a little turn with a wrench to make it snug.
And last but not least (but mt favorite) is improper grounding in the dwelling.

Some of the above can be easily corrected and/or checked and tested yourself. Some of them require a skilled electrician to troubleshoot and resolve.

bt-rtp


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## Chris Blount

Did you try a different set of wires going to the sub? Sometimes wires/connectors go bad for one reason or another.


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## BubblePuppy

Sometimes it is just a matter that one of the pieces of equipment is not properly grounded.


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## Greg Alsobrook

Chris Blount said:


> Did you try a different set of wires going to the sub? Sometimes wires/connectors go bad for one reason or another.


9 out of 10 times this has solved it for me...


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