A quick one, I hope. What are the correct DC resistance ranges for the voice coils in 16 ohm vs 8 ohm 2420 or other 1'' compression drivers that accept the current 2421 replacements (which are available in either 16 or 8 ohm versions, D16R2421 or D8R2421).
Reason I ask is that I recently purchased a pair of nominally 16 ohm 2420's on eBay, not with original wax seals. Upon opening them I found the aluminum diaphragm in one was damaged. I took both to A Brown Soun, authorized JBL Pro repair facility in Bay Area. I asked for both to be checked out and the bad diaphragm to be replaced with an aluminum version.
I had measured the DCR of both prior to bringing them in. One was 5.2 ohms, the other 5.4 ohms. The repair shop called me a couple weeks later and quoted me the price to install a new JBL diaphragm (which was about what I had expected) and said the other one was fine.
Then the guy said he would be ordering the 8 ohm part. I said, aren't they 16 ohm drivers, it says so on the label? He said no and that he had measured them himself, that I should have the 8 ohm to match. I said OK, since I haven't built the crossover network for these yet and figured I would compensate.
Today I get them back, and the new diaphragm measures DCR of about 2.5 ohms. I haven't installed these to test acoustic performance, since I haven't even built the cabs yet. But I am really questioning their statement and choice of parts. Thought i would consult the experts here before I go back to them.
Thanks in advance for the advice.