Can someone help me with a popping sound??

Hi all,
I'm having problems with a popping sound (sounds like rice cripies cereal) coming from my speaker & I think I've narrowed it down to possible interference from my subwoofer. My subwoofer seems to be emitting an electrical hum. Is it possible the hum is being picked up through my speaker cables & sent out through the speaker? The popping is only coming through the speaker closest to the subwoofer. If the culprit is the subwoofer, does anyone have any suggestions to fix this problem? I've got a picture posted of the speaker & subwoofer in the "system" portion of Audiogon, if you think this may help. I've straightened the cables out & separated them the best possible (better than the representation in the picture), but I don't have much room to work with. Any suggestions would be much appreciated. Thanks