I found a set of OW2 speakers at a local used record store. The foam has deteriorated on the cans. A buzzing in one had me fearing the worst. Turns out to be the foam debris on the woofer. I searched here on the forum.Many said to use various chemicals to dissolve the glue. After the years the glue on these had dried up. I cut the glue around the grill first using my "McGruder" knife. I made a tool out of an old nut pick to pry each hole above and around the lip. Popped off without chemicals. Buzzing gone and sound very good. Further restoration as time allows.