Fellow JBL enthusiasts,I have a pair of K2 S9900, I believe they are from 2011. My question is on the rubber edges of the woofer 1500Al-1, they are no longer completely black, but rather dark greyish. I uploaded a couple pictures. Anyway, is this to be expected? They feel fine, neither stiff nor sticky. Should I just go ahead and don't think of this, or should/can they be replaced (re-edged)? Thanks and best wishes,Sigurd Stefansson