The other day I was cleaning off my speakers (B&W 601's)...when I took off the faceplate, I noticed that the Tweeter dome on one of the speakers had "caved in". After testing both speakers (the other one was fine), I could not detect a difference in sound. Does anyone know if the sound quality is lessened by this? I would assume it is, but cannot tell by listening. I played several types of music and movies to try and discern. Thanks!