Anyone out there with speaker repair experience?

[rarredoa]

I have a Def-Tech Supercube Reference Sub. This sub is beyond powerful! Only problem is, that at very low frequencies, there is a very annoying little noise coming from the woofer when played at low volumes. The woofer makes a "scratchy"sound, kind of like buzzing, but goes away if i put just a tiny push on the woofer's surround, just touching it with my finger tip. Any ideas on what this may be? Is the woofer blown? Aside from this noise, the sub pumps out deep-bass at very loud levels. usually the noise can't be heard at higher volumes, but regardless i'd like to get this fixed. Any ideas?