Topic: my Sub has a humming sound....

[Sterling]

what happens when you plug it directly into the wall with nothing being fed into it?  especially when you turn up the volume on the sub?  anything there?

Nothing there...only when I plug in the live level.

Can you use a speaker level to send signal to the subwoofer instead of line level?  Does that make any difference?

I could use that but what speaker level would I put into it? All of them? Thats a pain in the ass but maybe the only way...the speaker level connections are for both front channels...

[krebsy]

Do you have a Cable TV signal coming into your system? I recently switched to a new amp, and I had a nasty hum problem crop up. After lots of seaching/reading I learned that a catv wire can lead to ground loops. As soon as I disconnected the Cable TV feed from my VCR, no hum.

[dnsacks]

when you tried the cheater plug, did you plug it into the top plug in the outlet or the bottom plug in the outlet?

This sounds a LOT like ground loop problem -- which is where 2 different grounded devices (your sub amp and another piece of gear) are both grounded and the hum is between the 2 grounded devices.  If you plugged the cheater plug into the top outlet, the metal ring on the bottom of the cheater plug would be touching the screw in the middle of the outlet and would be grounding the sub through the screw.  Plugging the cheater plug into the bottom plug should keep this from happening. 

When the sub is grounded, attaching the rca cable (or any cable) to the rest of your gear would cause it to share the ground with other devices and the hum would be back.

do any other devices in your audo system use 3 pronged plugs?

[Sterling]

when you tried the cheater plug, did you plug it into the top plug in the outlet or the bottom plug in the outlet?

The bottom plug.

do any other devices in your audo system use 3 pronged plugs?

No

I should perhaps be more clear about this hum...its actually house shaking! I can't turn the volume up on the sub at all when its attached via rca plug through the direct line, regardless of how its plugged into the wall.

I'm going to try and run it through the speaker wire level to see if that helps, in addition to using the cheater plug as well. I just thought it would so much easier to run one rca cable than both front channels from receiver to sub to speaker...

[Sterling]

Thanks to everyone for your help, I ran it speaker line and everything is fine  ...thanks again +T all around

[Genghis Cougar Mellen Khan]

Thanks to everyone for your help, I ran it speaker line and everything is fine  ...thanks again +T all around

Oktava 012 >>>> V3 >>>>Hosa ODL 276 >>>> JB3@44.1 >>>>wavelab 4.0

With your signature, I was thinking it could be an extra long cable run... 

Glad you got it figured out. 

[Sterling]

Thanks to everyone for your help, I ran it speaker line and everything is fine  ...thanks again +T all around

Oktava 012 >>>> V3 >>>>Hosa ODL 276 >>>> JB3@44.1 >>>>wavelab 4.0

With your signature, I was thinking it could be an extra long cable run...