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SteveJewels
07-31-2018, 11:26 AM
Hello,

I heard somewhere that there are two flavors of CD/diaphragms in the 4430, one for the early units and one for the late units.

Did I understand correctly? What are the two versions? How do you distinguish one from the other?

Best regards,

Steve
Ian Mackenzie
07-31-2018, 12:37 PM
The early one was aluminium diamond surround (NLA), JBL then changed everything to Titanium diamond surround (still available).
Radian make an aluminium diaphragm if you wish too try aluminium.
SteveJewels
07-31-2018, 01:48 PM
Thanks Ian.

So only the diaphragm changed? Did the part number change?

How do you determine which one it has?
grumpy
07-31-2018, 05:51 PM
The 2421 series (Alnico magnet, Al dia) looks very different compared to the later 2425/6 type driver (ferrite magnet, Ti dia)
SteveJewels
07-31-2018, 06:44 PM
The 2421 series (Alnico magnet, Al dia) looks very different compared to the later 2425/6 type driver (ferrite magnet, Ti dia)


Ahh, so they are different CD's. Thanks!

The JBL data sheet I have lists the CD's as 2425H. No mention of the 2421.
grumpy
08-01-2018, 07:28 AM
This thread might be of some interest.

http://www.audioheritage.org/vbulletin/showthread.php?34881-JBL-4435-Help
SteveJewels
08-01-2018, 07:02 PM
This thread might be of some interest.

http://www.audioheritage.org/vbulletin/showthread.php?34881-JBL-4435-Help


Very much so. Thank you.
markd51
08-04-2018, 01:27 PM
So Steve, did you get those 4430's you told me about? I'm gathering there was problems with the CD's then?
SteveJewels
08-04-2018, 03:04 PM
So Steve, did you get those 4430's you told me about? I'm gathering there was problems with the CD's then?

Hey Mark. I hope that you are happy and well.

It will be a few more weeks until I get up that way. If they are still available and I can come to an agreement on price with the guy, I will get them.

I did contact him. He thinks that they have the older Alnico/aluminum CD's. I don't think there is a problem per session but given their age the diaphragms might need to be replaced.

That leads to another question. How would one determine if the diaphragms were fatigued and did need to be replaced?

Or, what candidates are there for replacing the 2121's or 2425's?

Steve