I just replaced one of the midrange drivers on my Wharfedale Emerald center channel speaker. I had started to notice a buzzing sound from the right side driver when sound peaked, and confirmed it when I did a speaker balance with the AVIA disc. The buzzing became very noticeable with the AVIA noise signal (from the speaker balance test). Anyway, Wharfedale was very good about sending a replacement driver and I had the driver at my doorstep in just a few days after contacting IAG America (Wharfedale's rep in the U.S.). I replaced the driver and ran the AVIA noise signal again, and the buzzing was gone. I was than looking at the driver I replaced and trying to decide whether to keep it or just throw it out when I noticed the metal flange at one of the four attachment points was bent inward (in the direction of the speaker enclosure). It is very noticeable, and now I wonder if this could be the cause of the buzzing ??? If the metal flange did not seal properly against the enclosure at this point, would this potentially cause the buzzing I experienced ? I am also wondering if I could straighten it out, would I have a perfectly good spare driver ? I also have one somewhat related question. When I screwed the new driver back in place, I never got the sense of the screws getting progressively tighter and so I don't get the warm fuzzy feeling that the driver is sealed tightly against the speaker enclosure. Is there anything that can be done to improve the "tightness" of the seal, such as using wood filler in the screw holes ???