I have an old pair of Optimus 900 floorstanders that I've used for years. I thought they weren't sounding very good anymore, so I looked under the grill on one and saw that the foam surrounding the woofer had disintegrated! I think I remember reading somewhere that I can fix this. See attached picture... 1) Are these decent speakers, to begin with? 2) What do I need to do to fix the woofer? Thanks!