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Don M
01-03-2005, 10:40 AM
How difficult is it to replace a diaphragm? Are special tools or techniques required? Is the diaphragm self centering?

If this should be done by an authorized service center, can anyone recommend someone in the San Francisco Bay Area?

Don

paragon
01-03-2005, 10:50 AM
If you whant to use aftermaket dias, you have to try to fix them in the right position with a 1 kHz or lower sine wave.
You can move this dias a little around and you may put this in the right position.
No clues for original dias !!

Eckhard

Mr. Widget
01-03-2005, 11:15 AM
JBL diaphragms are "self centering" but do need to be installed with care and with the aid of a sweep test tone to make sure you are centered. There is wiggle room and the diaphragms must be wiggled. On more than one occasion I have needed to drill out the holes so that the guide pins would properly seat.

As for local authorized reconners in the Bay Area. There is A. Brown Soun in Marin, Audivex in Berkeley, and most likely there are several in the South Bay.

Widget

4313B
01-03-2005, 12:04 PM
"JBL diaphragms are "self centering""

I've got eight 2425H's here that say otherwise. No guide pins.
They absolutely have to be installed using a signal generator. 550 Hz for the 1" cores and 350 Hz for the 2" cores. ;)

Don M
01-03-2005, 01:13 PM
Thanks for the sage advice, I think I'll find a service center as I am without a signal generator.

This is a great website and after I have the diaphragms replaced, I will be back to ask for recommendations to improve my beloved 4320's.

Don