Many common diaphragms and HF drivers in stock. If not in stock can usually obtain within 4 to 5 days. If you have a blown diaphragm, inspect the crossover for damage, before replacing the diaphragm. Some crossovers have current limiting light bulbs that we also stock. Some bulbs are soldered in, some are in sockets. The filament may be burnt, or broken at one end or broken loose completely. In some crossovers, the tweeter may still work with a burned out bulb, but it won't get full power.