1.5" 2431H upgrade: should the 2435 BE diaphragm be the solution?

[Bruno_du_13]

Hello all,

I am new on this forum. I am found of JBL audio system since 25 years!

My system is an active 3 ways with 18" 2268H in vented box, a CMCD-81H 8" for the midrange (350 - 2kHz crossover points), and a 1.5" 2452H for the upper range.
At first, the HF driver was a 2431H Neodynium, but its frequency response was not good above 10kHz. And despite an efficient EQ with the the DP226 FAN, it doesn't sound very good.
So I replace it by a 2452H and it was a lot better.

By now; I would like to improve my 2431H, and I think about the Beryllium diaphragm of the 2435H. I would like to be sure both diaphragms are compatible (2431 vs 2435), and that a 2431 with a 2435 diaphragm is really equivalent to a 2435.

Many thanks in advance,

Regards

Bruno

[ivica]

Hello all, I am new on this forum. I am found of JBL audio system since 25 years! My system is an active 3 ways with 18" 2268H in vented box, a CMCD-81H 8" for the midrange (350 - 2kHz crossover points), and a 1.5" 2452H for the upper range. At first, the HF driver was a 2431H Neodynium, but its frequency response was not good above 10kHz. And despite an efficient EQ with the the DP226 FAN, it doesn't sound very good. So I replace it by a 2452H and it was a lot better. By now; I would like to improve my 2431H, and I think about the Beryllium diaphragm of the 2435H. I would like to be sure both diaphragms are compatible (2431 vs 2435), and that a 2431 with a 2435 diaphragm is really equivalent to a 2435. Many thanks in advance, Regards Bruno

Hi Bruno,

why not use UHF driver over 10kHz such as:

jbl 2408-1 or
bms4540 or
jbl 2405 or
faital_pro_hf104

that are intended to be used in such frequency range.

regards ivica

[Bruno_du_13]

Hi Ivica,

I do not want to have a 4 ways system... it would imply to change the crossover, add another amplifier (I want to stay in fully active filtering), and have more phase rotations. And the UHF could not be placed very close to the HF horn in my system.

I can keep the 2452, which is a very good driver, but the BE diaphragm should allow extended HF and better waterfall/CSD due to its excellent damping.

Thanks!

[ivica]

Hi Ivica,

I do not want to have a 4 ways system... it would imply to change the crossover, add another amplifier (I want to stay in fully active filtering), and have more phase rotations. And the UHF could not be placed very close to the HF horn in my system.

I can keep the 2452, which is a very good driver, but the BE diaphragm should allow extended HF and better waterfall/CSD due to its excellent damping.

Thanks!

Hi Bruno,

using active (digital) network, spacial difference between VHF and UHF drivers can be 'time' compensated.

using 4" diaphragm, may be you can reach 15~16kHz, but I think You have to use JBL Be diaphragm, or JBL Aluminum, not Truextent, but here on the Forum lot of members has much, much more experience in that field then me,

regards
ivica

[cooky1257]

Hi, to answer your question yes a 2435 Be will drop into a 2431.
With your XTA 226 you should be able to eq it out to about 15khz with good results-I wouldn't push them further, as I recall the PT's work well with this driver(use the search function i think Zilch did a lot of experimentation a few years ago).
I'm using an XTA 224. My SAM1 horns have the 2435 Be and are good up to about 14khz.
I also use 2452 with Truextent Be on H9800 horns and enjoy good flat clean output up to about 14khz where I let them roll off naturally.
What the Be will give you is lower distortion, less colouration, more clarity and detail, it isn't necessarily a more extended response but it will be of a higher quality.

[Bruno_du_13]

Thank you very much Cooky1257! very interesting.

So no more HF extension... but better quality up to 14kHz.
I will search on the forum for Zilch experimentaions.

Thanks!

[Didier]

Hello,
As it seems that the main problem with 2431H and 2435HPL is the throat with some horns,
Did someone compared those drivers to the 2432H?
As pos said, maybe this different core could solve the high frequency problems...?
If yes, it would be also interresting to compare Al, Ti and Be in this driver
Didier