Loud buzz in sub woofer, soundbar sounds fine

MAKE SURE IT HOOK UP RIGHT FORONE

Check the receiver in the speaker and the amplifier. they both have to work to get sound.

Select Start > (right click) My Computer > Manage
In the Management window select > Device Manager
Next to Sound, Video and Game Controllers click the + sign
A yellow triangle will signify a problem so if one is present, right-click that device and select Properties
You can then choose to update the driver
For more details check Dell Xps 420 Manual.
Dell Xps 420 Manual

Your sub woofer is not mean for voice sound...check that you have connected the systen up properly and that you have put the sub woofer into its wn connection..if it is in the right connection the woofer could be blown.also try decrease the midrange hurts on the woofer

I just bought mine yesterday and have the same problem... did you find a solution (other than throwing it out the window)?

If the woofer works fine when plugged into any other port, I would say that you have a connector on the receiver that has a loose connection or possibly a cold solder joint (poor or broken solder joint). RCA jacks can be stressed quite a lot especially if you use cables that have very tight connectors. The female RCA jack gets wiggled or twisted when trying to remove a cable and this causes solder joints to crack. I would have a look at that connector on the receiver..

Replace the lead to the sub.
Thanks Guy9

often your sub need to be change because of its malefunction.