View Full Version : 2450S & 2451S confusion

Dave Zan
09-22-2004, 03:39 AM
Does anyone understand the 2450S and 2451S differences?

The 2450H and 2450J are both 2" drivers. 8 and 16 ohm respectively.
Similarly the 2451H and 2451J are both 1.5" drivers in 8 and 16 ohm.
The two H's uses the same repair kit and similarly the two J's.
I.e Just the exit body differs.

I believed the 'S' models were a later version with a non ribbed and Aquaplas dusted dome/dia.
So I assumed the model names would follow the same pattern.

Not true! - In fact the 2450SL is actually a 1.5" driver with a unique repair kit in 8 ohm only.
The 2451SLJ has a unique repair kit in 16 ohm only.

Is this just an inconsistent nomenclature issue?
I.e. The consistent name for the 2450SL would be 2451SLH ?
Or is there some other difference in the driver that makes sense to call it a 2450 rather than a 2451?

As a DMS-1 wannahave I wanna know!

09-22-2004, 03:45 AM
Hi Dave!

Nice that you posted this. Yesterday evening I searched all older threads (mainly from Niklas Nord) that deal with this issue.
Result was that I ended even more confused.

Hope the techbots can help!

Maron Horonzakz
09-22-2004, 10:42 AM
I believe you can install the 2450 SL diaphram into the 2450 driver. That part is interchangeable. More enlightenment is needed on this subject.

Dave Zan
09-23-2004, 01:27 AM
JBL service sent me this URL.

As far as I can tell a 2450SL could have been more consistently called a 2451SLH.

I.e. If you put a 2450SL repair kit in a 2450 you will end up with a transducer that does not match any JBL part.
If you put a 2450SL repair kit in a 2451 you will end up with a 2450SL.

Maron Horonzakz
09-23-2004, 06:38 AM
The whole idea in putting the 2450SL powder coated aquaplas diaphram into any JBL large driver is to smooth out any resonence or spikes that may occure. And probably sound more like the alumunum diaphrams with the longivity of titanium . No confusion just audio TWEEKING. If it sounds good, feels good , why not?

Dave Zan
09-23-2004, 07:26 PM
I didn't mean to imply that it is a problem to end up with a parts match that JBL never made.

I only meant to point out the inconsistent nomenclature.
One would expect that a 2450H or J driver with a 2450SL replacement kit would be a 2450SL - and it certainly isn't!

To use the SL parts for the reason you state is probably an excellent idea
If you try the replacement then please tell us how it works.

09-25-2004, 08:02 PM
Well I have some of *each* parked in the shop:

The 2450SL ( 1.5" ) has the 2445 diaphram ( D8R2450SL ) that is powder coated for use in the Array and DMS systems. It has the NARROW bolt pattern to mate with the array horn.

The Later model 2450SL-A used the RIBBED diaphram ( D8R2450SL-A ) and is also powder coated.

These are the SAME DRIVER as the 2451 EXCEPT that it's horn bolt pattern is **wider** to mate with the 2381 ( SRX ) and 245X horns.

Any of these diaphrams are interchangeable but to keep you on your toes, the 2450S and 2451S are actually the PHENOLIC DIAPHRAM models that replaced the heavy 2485....and of course the gap AND the diaphram mounting pattern are different...

btw the coated diaphram is the nuts for up close stage monitors.


"above all else confusion reigns"

Maron Horonzakz
09-26-2004, 07:43 AM
The 2450S and 2451S are phenaulic ? I wonder how low you can crossover those drivers.

09-26-2004, 04:04 PM
Well the web has this info - I could not find the "S" variant anywhere...

Back in the old alnico days JBL used the "SP / HP" suffixes to denote the phenolic version ( IE: 375HP and LE100S )



Another possibility is the current "S" version denotes the thread-on model ( the 1" driver as used in the 15" JBL/urei coaxial models was labeled 2425HS )

This also shows up in some of the install models in the ferrite 2" version ( must be one helluve thread! ) but I cannot find that exact model. Look at the SP and VS:


Dave Zan
09-26-2004, 09:29 PM
Subwoof wrote

The 2450SL ( 1.5" ) has the 2445 diaphram ( D8R2450SL ) that is powder coated for use in the Array and DMS systems. It has the NARROW bolt pattern to mate with the array horn.

Now I _am_ confused - because I purchased a 2332 horn and it fitted on my 2447 driver with the 115 mm bolt circle. The Sound Power series also use the 2447 and the 2332 horn.
But the 2332 is supposedly used in the DMS-1 with the 2450SL-A and therefore should have a smaller bolt circle.

Hmmm. Different versions of the 2332 horn despite identical part numbers?

Perhaps I will solve the problem with a lateral approach - just buy TAD400 x

09-27-2004, 05:10 AM
The 2332 horn supports both diameter mounting holes - the 2381 and 2352 only support the larger diameter ( 2447 ) but can be drilled out if needed.

It is impossible to document all the possible combinations with these because jbl does NOT publicly publish detailed "technical" cut sheet for anything that is not on the regular component sales list.

Sometimes they have them in-house but you have to call and pretend you know what you are talking about.

And only a scattering of info is found on the assembled cabinet breakouts...

so you gotta buy and try..


Dave Zan
09-29-2004, 03:13 AM
The 2332 horn supports both diameter mounting holes

I sure don't remember 2 sets of holes - the horn is stored at a friend's place about 10,000 Km away so it's a bit hard to check.

So what bolt circle do the 2430 and 2431 use?

11-21-2004, 07:48 AM
Hello all.

Here are two pictures of my 2332/2451 combination. The pictures does show dual bolt patterns.


best regards

11-21-2004, 08:56 AM
Robert - what are you using the 2332/2451 combo in? Is it for home, studio, or pro sound reinforcement use? What other components, and crossover info? Do you like the way it sounds? I've really considered a similar combination, (but using the 2430 instead of 2451 - $$$). It looks like the 2332 is cast, (aluminum?). And it also looks like you have a thin strip of velcro along the bottom - purpose?


11-21-2004, 10:31 AM

This is maybe a little of topic in this thread so I made a new thread under general called Just annother HT.