Need Diaphragm for 375 driver

[Eric M.]

My 375 diaphragm needs to be replaced. Can anyone tell me where to get an original JBL or aftermarket if original is not available?
Simply Speakers thinks the 2445J (D16R2445) is the same. Can anyone confirm this? If so, will if sound different than the other 375? Should I replace both diaphragms at the same time?

Thanks,

Eric M.

[speakerdave]

If you have an original 375 (aka 2440) diaphragm, exact replacements are no longer available, sadly. The 2441 is also made of aluminum and would fit, but it has a different suspension, different response and would sound different. The 2445 is titanium and even more different. There is an after market beryllium option also. Unless you can find NOS 2440's you will need to make a choice and buy two.

Photos of your present diaphragm would help by grounding this discussion in the actual.


Bg

My 375 diaphragm needs to be replaced. Can anyone tell me where to get an original JBL or aftermarket if original is not available?
Simply Speakers thinks the 2445J (D16R2445) is the same. Can anyone confirm this? If so, will if sound different than the other 375? Should I replace both diaphragms at the same time?

Thanks,

Eric M.

[Eric M.]

Thanks Dave,

I am out of town but will post pictures when I get back. It looks like I will have to replace the pair.
Which of the diaphragms would you recommend and where is a good place to get them? I'm running the 375 from 2400Hz to 7000Hz.
Something odd I'd like to run by you. I just bought this pair of 375s. The one in question still has the wax plugs so, I'm guessing it is the original diaphragm (although I do see they sell aftermarkets wax plugs). This unit still works but is considerably quieter than the other. The good unit measures 8.7 ohms. I was told the other was 10.4 ohms. When I pulled it out of the box, it measured 52 ohms. After playing it for an hour, it dropped to 34 ohms. This AM it was 138 ohms, but still sound comes out, just not as loud. Could there be another issue? i was thinking old solder joint inside?

Thanks for your help. I see you're in N CA. I'm in Oakland.

Eric M.

If you have an original 375 (aka 2440) diaphragm, exact replacements are no longer available, sadly. The 2441 is also made of aluminum and would fit, but it has a different suspension, different response and would sound different. The 2445 is titanium and even more different. There is an after market beryllium option also. Unless you can find NOS 2440's you will need to make a choice and buy two.

Photos of your present diaphragm would help by grounding this discussion in the actual.


Bg

[speakerdave]

Actually, there is one more option, which may be the best, short of the significant investment in beryllium. There is an aquaplas dusted version of the titanium diaphragm that was developed for the new drivers with 1.5 inch throats. It will fit the older 4" diaphragmed drivers with two inch throats. The aquaplas improves internal damping and smooths response. You can get them at Speaker Exchange.

[speakerdave]

The DCR number wouldn't jump around that way absent an iffy connection, which would also explain the low output.

[Eric M.]

Just looked at the beryllium option. Yep, that's out!
I'll check for bad connections, maybe I'll get lucky. I'll post pictures at that time as well.
Do you know off hand what the model # is for the aquaplas dusted version? I checked their site and could not find anything. OR, if I call, will they know what I'm asking for.

Thanks again.

Eric

Actually, there is one more option, which may be the best, short of the significant investment in beryllium. There is an aquaplas dusted version of the titanium diaphragm that was developed for the new drivers with 1.5 inch throats. It will fit the older 4" diaphragmed drivers with two inch throats. The aquaplas improves internal damping and smooths response. You can get them at Speaker Exchange.

[speakerdave]

D16r2451sl

[Mr. Widget]

I'd replace both with originals. JBL blew them out recently and they are available here for $125 ea. which is a very good price... doubly good when you factor in that when these are gone there will likely never be another run of them.


Widget

[speakerdave]

Oooh! Nice pickup, Widget. Thank you. I must have been thinking of the 2420.

[Eric M.]

I got lucky. Took it apart and took a look around. It seemed there was a bad connection from the voice coil copper ribbon wire to the terminal which the internal wiring connect to. I bent a short length of stranded copper wire and tinned it. Laid it over the ribbon wire and the terminal and soldered in place. I'm down to 8.1 ohms, the level is the same as the other 375. I ran it for a few hours just to make sure all is well. See pictures. Also, I took pics of both diaphragms, can you tell me if these are original?

Thanks for the help.

[speakerdave]

Nice fix! I've never seen one, but I think they are original: aluminum, half roll surround.

[sguttag]

Note, I'm showing that I can still order the D16R2440 with a ship date from JBL within April. JBL does like to be optimistic about things that they don't have on the shelf but it appears that it is still available.