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View Full Version : JBL 2" Exit Drivers Diaphragm Recommendation



ra7
11-20-2020, 09:25 PM
Yes, I know there are many other threads with this title. But this one is new :)

I've been using the stock titanium diaphragms in the 2445Js with the 2380 horn. It sounds absolutely magical. Over the years, I've had many compression drivers and many horns, but nothing sounds like this. I also have the BMS 4590, which is a state-of-the-art 2" exit dual diaphragm coaxial driver. While it sounds more refined, especially in the last octave, the 2445/2380 combo has holographic imaging, with a tangible feel to instruments, speakers completely disappear, and music actually sounds like being played by people. It is not the crossover because I'm getting good phase overlap with both drivers with the woofer, and I also use FIR correction, so the tonal balance is the same in both instances. The 2445/2380 is just better.

So, I'm wondering if I should splurge on the Truextent Be diaphragms. Other recommendations include the aquaplas "SL" versions of 2450 diaphragm. But I cannot find those in stock anywhere, not even on ebay.

So, got any recommendations about what to do?

macsic
11-21-2020, 08:19 AM
Hello, I currently have 2450/2397s with "SL" aquaplas diaphragms from 2451 drivers that I bought to have their diaphragms that I couldn't find either, I interchanged the diaphragms and I I sold the 2451 with the Titanium Ribbed diaphragms quite easily. The aquaplas are really less harsh and I prefer them for the use I make of them at home.
I've never heard of Truextent Be and maybe it's better for my wallet ;-)

ra7
11-21-2020, 03:26 PM
Thanks! That is a neat idea. I'll be checking ebay.

Have the 2450 diaphragms been officially discountinued or are they just out of stock?

grumpy
11-21-2020, 05:05 PM
One potential vendor (no association):

https://reconingspeakers.com/product/jbl-d8r2450sl-diaphragm/

likely out of stock due to the sale price.

Don't recall the difference (would think there's -something- or why two part numbers? I just don't remember... maybe someone else does)

https://reconingspeakers.com/product/jbl-2452sl-d8r2452sl-diaphragm/

srm51555
11-21-2020, 05:52 PM
I waited about a month to get mine.

I signed up for the email list and it went to my junk folder FYI.

Also if you running a two way system the truextent’s are not as nice as the 2450sl’s due to its hf roll off

Thanks,
Scott

ra7
11-21-2020, 06:07 PM
Good to know, thanks Scott!


One potential vendor (no association):

https://reconingspeakers.com/product/jbl-d8r2450sl-diaphragm/

likely out of stock due to the sale price.

Don't recall the difference (would think there's -something- or why two part numbers? I just don't remember... maybe someone else does)

https://reconingspeakers.com/product/jbl-2452sl-d8r2452sl-diaphragm/

Grumpy, thanks! The second link seems to be for a 2452. Are you sure those will work in a 2445, 2" exit driver? Reconing Speakers do not provide a spec sheet for the diaphragm, so, not sure about their size.

Also, both the links are for 8 ohm drivers. The 2445s I have are 16 ohm. I presume the 8 ohm diaphragms won't work in a 16 ohm driver because, presumably, there are other differences (field strength, etc.).

JeffW
11-21-2020, 06:40 PM
The 8 vs 16 is determined by the voice coil of the diaphragm. I think the reason the 2452 is called out different than the 2450 is just the way the speaker binding posts come through the back cover of the 2452. I have some 2452 and don't remember anything else different - I haven't bought any 2452 specific diaphragms and I think generally speaking all the 4in coil diaphragms except the phenolic versions are more or less physically interchangeable. The 1.5in vs 2in is just the hole where the sound comes out, 4in voice coil is the common element.

The D16R2451SL is the 16 ohm coated model number you are looking for, it'll break some hearts if it really is discontinued.

grumpy
11-21-2020, 11:00 PM
Doh. I glossed over the “J” suffix. Sorry about that.
Wondered about the direct terminal connection... as both pictures looked identical.
IIRC, the old screws and connecting wires work fine with the “new” dias.

ra7
11-22-2020, 04:42 PM
If there is indeed no difference in the flux density between the H/J models, which it appears there is none, then there is an D8R SL diaphragm that is available and could work. Right?

grumpy
11-22-2020, 06:00 PM
Yes. But if you're using a passive crossover, it would need to be modified and levels possibly adjusted.
With an electronic crossover/biamp system, it should be much less of an issue.

DogBox
11-23-2020, 04:18 AM
Yes. But if you're....

[No Association] https://reconingspeakers.com/product/bex4016-truextent-beryllium-diaphragm-16-ohm-copy/ with some drivers for fitment and some

Specifications thrown in!

I think 2440/2441 threads got around to mentioning these 'Beryllium' diaphragms and were the ultimate in choice...

Outa my price-range..:o:

Steve

Bassdabob
02-04-2021, 11:55 AM
Hello,

D16R2451SL are again avaiable via JBL !

Regards