I bought a pair of these about a month ago. I had a rattle in one of the speakers. I took it out and could not find anything wrong with it. Someone suggested I try turning it 180 degrees and this did not help. I am in the process of ordering one. I took the others out to inspect them also. I had noticed at the back of the speakers where the cone connects to the corrugated paper looking white backing that is there is a power or chalking around this area. Should I be concerned? If I am going to replace the one speaker and this is a sign of the speakers getting old I am thinking of doing all while I can still get them. Does anyone know the general life of these speakers or what the chalking looking stuff is? It looks as it is either coming from the Corrugated paper or is it a glue or something where the cone and paper meet?