Hi all,
I would like to improve a pair of JBL 2431H (Neodynium 1.5" HF driver).
It is an interesting, recent driver (low weight 2.7lbs, 1.95T induction), which has replaced ceramic magnet drivers like the 2452.
But its frequency response is not so flat above 10kHz.
Here is its frequency response mesured on a plane wave tube:
Should it be possible to change its diaphragm for a better one (like the 2452's one for example)? or anyway to improve this 2431?
Thanks in advance,
Regards
I would like to improve a pair of JBL 2431H (Neodynium 1.5" HF driver).
It is an interesting, recent driver (low weight 2.7lbs, 1.95T induction), which has replaced ceramic magnet drivers like the 2452.
But its frequency response is not so flat above 10kHz.
Here is its frequency response mesured on a plane wave tube:
Should it be possible to change its diaphragm for a better one (like the 2452's one for example)? or anyway to improve this 2431?
Thanks in advance,
Regards
Massilia,
Pretty much all 3" diaphragm drivers will have some VHF peaks and dips.
The 2452 diaphragm is all titanium, not likely to be an improvement regarding smooth response. The Mylar surround on the 2431 probably makes it as smooth as you will get from JBL.
I would suggest using parametric EQ to take out the 2431's peak around 14,500 Hz, but first measure yours on whatever horn you use to see if it has the same peak as "Line Std #33 on a 2" tube using a 1.5" adapter".
Art
2452 is 4" neo with ribbed phragm, 2452-SL with aquaplased phragm.
Pics and measurements: 2450 Dia - Page 7
Don't know\remember about SL or Be phragms for 2431.
Pics and measurements: 2450 Dia - Page 7
Don't know\remember about SL or Be phragms for 2431.
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Thank you very much for your responses.
I tried to make an EQ (using the XTA DP226 active filter) on my 2431 mounted on a JBL PT horn... the response above 10kHz was very bad before. But despite this correction, the sound quality remained rather poor...
For the moment I have replaced the 2431 drivers by the 2452 (thanks for the precision that it uses a 4" diaphragm), its sounds a lot better and needs a raisonnable EQ to be flattened. The inconvenient is that the weight is considerably higher.
So I note the possibility to use the 2435 diaphragm, which seems indeed more flat. Do someone know if 2431 uses ferrofluid, and if it is not too difficult to change the diaphragm for a non-expert?
And where to buy the 2435 diaphragm?
Thanks in advance,
Regards
I tried to make an EQ (using the XTA DP226 active filter) on my 2431 mounted on a JBL PT horn... the response above 10kHz was very bad before. But despite this correction, the sound quality remained rather poor...
For the moment I have replaced the 2431 drivers by the 2452 (thanks for the precision that it uses a 4" diaphragm), its sounds a lot better and needs a raisonnable EQ to be flattened. The inconvenient is that the weight is considerably higher.
So I note the possibility to use the 2435 diaphragm, which seems indeed more flat. Do someone know if 2431 uses ferrofluid, and if it is not too difficult to change the diaphragm for a non-expert?
And where to buy the 2435 diaphragm?
Thanks in advance,
Regards
Thank. Others suppliers are possible among the recone-kit specialists. About 700$/part indeed, plus customs taxes from US to France, Europe...
Anyway; can someone tell me if 2431H uses ferrofluid, and if it is difficult to exchange the diaphragm for a non-specialist ?
This Beryllium diaphragm seems very interesting (very low weight, higher mass-breakpoint) for an audiophile usage.
Thanks in advance!
Anyway; can someone tell me if 2431H uses ferrofluid, and if it is difficult to exchange the diaphragm for a non-specialist ?
This Beryllium diaphragm seems very interesting (very low weight, higher mass-breakpoint) for an audiophile usage.
Thanks in advance!
This says 'yes', providing it in a replacement kit: Amazon.com: JBL Factory Speaker Replacement Diaphragm D8R2431, 2431H, 339894-002X, and many others: Electronics
Do not know anything about actually doing a replacement.
Yes, ideally Be is the way to go for HIFI if no super tweeter horn is used.
GM
Do not know anything about actually doing a replacement.
Yes, ideally Be is the way to go for HIFI if no super tweeter horn is used.
GM
Thank you GM.
I asked also to "the Speaker Exchange"; they have a response from JBL saying that:
" As far as I know the primary difference between these is beryllium vs. titanium diaphragm membranes. I have heard of this being done in the field but it is not something that we recommend in any of our documentation.”
-> The diaphragm exchange from 2431 to 2435 seems possible but not guaranteed.
And they confirm me that it uses ferrofluid. Problem, I don't know how removing it and correctly put it in with the new diaphragm...
I asked also to "the Speaker Exchange"; they have a response from JBL saying that:
" As far as I know the primary difference between these is beryllium vs. titanium diaphragm membranes. I have heard of this being done in the field but it is not something that we recommend in any of our documentation.”
-> The diaphragm exchange from 2431 to 2435 seems possible but not guaranteed.
And they confirm me that it uses ferrofluid. Problem, I don't know how removing it and correctly put it in with the new diaphragm...
You're welcome!
As Flaesh implied, the Lansing forum is the 'go to' place for all 'things' JBL.
I assume there is instructions in the replacement kit, but GOOGLE is your friend 😉 for just about any information you desire these days, though of course best to read a variety of responses since there's plenty of erroneous information available too: https://www.google.com/webhp?source... compression driver diaphragm with ferrofluid
GM
A kit comes with new ferrofluid.
The old fluid is wicked out with some paper card stock, then the new is squeezed in from the plastic pouch.
It may be cheaper to buy used 2435 and change the ferrofluid rather than buy diaphragms. Plus, the 2431 can be resold if desired.
The old fluid is wicked out with some paper card stock, then the new is squeezed in from the plastic pouch.
It may be cheaper to buy used 2435 and change the ferrofluid rather than buy diaphragms. Plus, the 2431 can be resold if desired.
Thank you for your response!
GM, I have created a profil on Audioheritage but I am still waiting for its validation.
DJK, I try to sell my pair of 2431 since more than one year... they have been very little used and only as an audiophile usage, they are as new ones. But here in France nobody is interested.
So if I can upgrade it as a 2435 with its exceptionnal Beryllium diaphragm, it's interesting to upgrade my audio system.
I have the confirmation of the 2435 diaphragm availability. Just have to be sure 2435 and 2431 diaphragms can be exchanged, and that a 2431 with a 2435 diaphragm is truely equivalent to a 2435 driver.
Thanks!
GM, I have created a profil on Audioheritage but I am still waiting for its validation.
DJK, I try to sell my pair of 2431 since more than one year... they have been very little used and only as an audiophile usage, they are as new ones. But here in France nobody is interested.
So if I can upgrade it as a 2435 with its exceptionnal Beryllium diaphragm, it's interesting to upgrade my audio system.
I have the confirmation of the 2435 diaphragm availability. Just have to be sure 2435 and 2431 diaphragms can be exchanged, and that a 2431 with a 2435 diaphragm is truely equivalent to a 2435 driver.
Thanks!
The JBL PT horn is for a 1.5" driver. It is included with the JBL CMCD 8" PT horn in the same assembly. No matter to change it (and for me it's a good unit: extremly low distortion, flat frequency response for the CMCD; low distortion and extended bandwidth for the 1.5").
🙂
🙂
Thank you Flaesh.
In fact, today I use the 2452 JBL as the 1.5" driver. It is OK for me, it is rather similar than the 2446 response: a good driver.
But, since I have two 2431 unused (due to their poor response above 10kHz), I would like to improve it. If I can upgrade it as a 2435, excellent due to its Beryllium diaphragm, let's do it!
If not, I will keep my 2452, which are already greats. No real need to change it... just an audiophile little delire! ;-)
Thanks!
In fact, today I use the 2452 JBL as the 1.5" driver. It is OK for me, it is rather similar than the 2446 response: a good driver.
But, since I have two 2431 unused (due to their poor response above 10kHz), I would like to improve it. If I can upgrade it as a 2435, excellent due to its Beryllium diaphragm, let's do it!
If not, I will keep my 2452, which are already greats. No real need to change it... just an audiophile little delire! ;-)
Thanks!
Clear! 🙂
Aforementioned (and by wrager today) 2452 + IIRC about $120 SL phragm is one of the options that I considered for my tweeterless system.
But now I bought cheap plastic 😀 D2..
Aforementioned (and by wrager today) 2452 + IIRC about $120 SL phragm is one of the options that I considered for my tweeterless system.
But now I bought cheap plastic 😀 D2..
Does it mean "2452 is less greats than 2431"?
Flaesh,
2452 is significantly better than 2431. 2452 response is relatively similar to 2446's one. That's the reason I replaced the 2431 by the 2452 in my system.
But 2431 with a 2435 diaphragm should be better than the 2452 (due to BE diaphragm), and furthermore should lower the weight of my loudspeakers.
2452 is significantly better than 2431. 2452 response is relatively similar to 2446's one. That's the reason I replaced the 2431 by the 2452 in my system.
But 2431 with a 2435 diaphragm should be better than the 2452 (due to BE diaphragm), and furthermore should lower the weight of my loudspeakers.
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