I hope you don't mind me jumping on this thread, but I have a pair of James's early Ergo IXs cabinets and crossovers. They are nice speakers. Actually, mine are probably an early crossover design which was later improved with a capacitor change that mine don't have (yet). Anyway, a friend helped me put them together (I bought the cabinets and crossovers from someone who James had made them for) and there is just a folded piece of polystyrene formboard for dampening in the cabinets. My friend insisted this was best. I've always wondered about his thinking on this and whether I am getting the most out of them. I didn't agree with him at the time, but he was helping me out. Should I change this and stuff them with rockwool or such? Perhaps I should also get that capacitor changed on the crossover too?