Subwoofer Hum...How to remedy?

[FuzzyReets]

Hi folks. I have a Yamaha RX-V465 receiver and a small 10" Polk sub. I get some hum out of the sub even when the receiver is off. I noticed that when I unplug the receiver that the hum goes away. I'm not sure if this means that there is a problem with the receiver or not. From a google search it seems like hum is a pretty common thing from subs but I'm not sure how to fix it. Looking for help. Thanks!

 

[jonnythan]

Either try a 3-prong to 2-prong adapter or run an extension cord and plug the sub into the same place the receiver is plugged in. Chances are one of those will fix it.

 

[BoredSysAdmin]

Either try a 3-prong to 2-prong adapter or run an extension cord and plug the sub into the same place the receiver is plugged in. Chances are one of those will fix it.

"3-prong to 2-prong adapter" is the likely the CAUSE of this problem, not the fix...
Google "Fixing Ground Loop" - this is what you got

http://www.audioholics.com/tweaks/connecting-your-system/ground-loops-eliminating-system-hum-and-buzz

 

[jonnythan]

"3-prong to 2-prong adapter" is the likely the CAUSE of this problem, not the fix...
Google "Fixing Ground Loop" - this is what you got

http://www.audioholics.com/tweaks/connecting-your-system/ground-loops-eliminating-system-hum-and-buzz

Well, the article mentions that it might reduce safety, not that it doesn't work. It does, in fact, usually fix the problem 100%. If you're not comfortable with it, plugging the sub into the same power strip as the receiver typically fixes it too.

 

[ratso]

please fix ground loops the right way (safely)

http://www.jensen-transformers.com/

 

[bikdav]

Good Thought

Either try a 3-prong to 2-prong adapter or run an extension cord and plug the sub into the same place the receiver is plugged in. Chances are one of those will fix it.

Jonnythan's idea is far and away the best thing to try first. Normally with subwoofers that is the problem. But, if that problem still persists, you might want to try putting a ground loop isolator on the RCA connector between the sub and the receiver. Normally, those are used in car stereo installations. But at someone else's suggestion, I stuck one between my PC and the receiver to cut out a terribly loud hum. It reduced that hum to almost nothing. I was awe struck by that trick.

 

[jonnythan]

I've used GLIs here and there, particularly in my car when I had an iPod and auxiliary input both wired into the head unit. They worked, but they cut the level down a little bit and seemed to compress the dynamics slightly. I'm sure you could get a more expensive one that might do better though. The only way a cheater plug could really cause any damage is if you have a serious wiring fault in your house, in which case you could get some current flowing through your sub cable.