Hello, I've got an EXCELLANT pair of 617-8a's but 1 needs a diaphram for the HF. ANYONE KNOW WHERE one can be bought? Also, I haven't hooked them up to a speaker can or system as of yet but was told to do a "reverse polarity" hook up on them.. Is this correct? I don't want to mess them up by hooking them up incorrectly so I figure questions before I screw them up. With this driver, any special things need to be done before installing them in the cabs? (just picked up the original cabs) thanks a ton.. Any help with polarity would be great ! Thanks.. Mjclemm...