Any clue where to get 617-8a diaphrams? Installation?

[M Clemmer]

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...

[Earl K]

Here's the Altec Spec Sheet for this model .

Call GPA to see if they have replacement parts for these 12" ceiling speakers .

I'd always flip ( as a start ) the polarity of the HF leg of any 12 db per octave crossover . I would then measure the system response ( with an RTA ) to see how things worked out with that configuration . If you can't measure / just flip the HF polarity & call it good ( instead of fliiping the HF polarity, you have the option of flipping the LF polarity / but just flip one or the other ) .