JBL 4338 al to 4338 full Be ?

[caladois]

If I upgrade my 4338 with Be drivers, will it match ?

I have an opportunity on Be drivers, and I was thinking of replace the 435al and 045ti withe a full Be set up (435be + 045be) ?

Do you think it will perform the system even if it's possible ? I am very happy at the moment.
Impedance are the same. I am afraid by the fact of a crossover design specific to a type of driver. I don't want to desequilivrate the response of the speaker.
Please let me know if I could make a mistake.

[Earl K]

Here we see both of the refurbished 2435s are now nicely matched. We can also compare them to a pair of nicely matched 2431s on the same 100° by 100° PT-F wave guides. The 2435s appear to be slightly smoother in response and also about 3dB more sensitive .

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=9040&stc=1&d=1121751838
Here we compared the 2435 with the 435Be, the 2430 and 2431 drivers all on the H9800 horn. The response of the 2435 and the 435Be were essentially identical. The effects of the larger back cap and lack of ferro fluid of the 435Be was not noticeable in the frequency response measurement. It is quite possible that a subjective listening test would show a difference, but from strictly a frequency response measurement, they do appear very similar.

This series of measurements has shown us that there are potential hazards in buying used and untested merchandise, luckily JBL was able to come to the rescue. It also shows us a nice comparison of almost the full line of JBL's current crop of 1.5" exit 3" diaphragm drivers.
http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=9044&stc=1&d=1121753057

Here we see that the low end performance of the 435Be, 2435HPL, and 2431 are all quite good. It would seem that the larger back cap isn't necessary for performance below 1000Hz. We did not do any listening tests or power tests measuring distortion, but the initial measurements were surprisingly encouraging. I am not sure if it is due to the back cap or other tweaks, but the 435Be did exhibit, albeit by a small margin, the flattest overall response of the three.
http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=7965&stc=1&d=1117355669



If I upgrade my 4338 with Be drivers, will it match ?

I have an opportunity on Be drivers, and I was thinking of replace the 435al and 045ti withe a full Be set up (435be + 045be) ?

Do you think it will perform the system even if it's possible ? I am very happy at the moment.
Impedance are the same. I am afraid by the fact of a crossover design specific to a type of driver. I don't want to desequilivrate the response of the speaker.
Please let me know if I could make a mistake.

- The 435Be ( 2435 ) was shown ( by Mr. Widget ) to be a few db more sensitive in his above studies .

- So, IMHO, it's a poor idea if you think the new drivers will just drop-in as a "plug & play" /giving instant improvement .
- The resistive padding in the crossover will need some tweaking to accomodate the different driver types .

- OTOH, I believe it's quite a good idea of you hire someone like 4313B ( or maybe someone on your side of the Atlantic) to make all 3 parts match up correctly . ( ie; I feel if you can afford to buy the drivers /you should be able to afford to pay for a pros' services to optimize the swap ) .

- You'll "want" to send all the drivers ( new or used ) in for "matching" purposes / with the understanding that if they're too far out of specification ( to fix with simple LCR adjustments within the crossover ) that you'll pay to have new "matching" diaphragms , installed .




http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=22497&stc=1&d=1170461963
http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=33494&stc=1&d=1217361268
- Compare for yourself the FR curves of the two models of drivers .
- I see ( from Widgets' studies ) when healthy drivers are compared on 3 different horns/waveguides / they pretty closely track ( parallel ) each others' curves .

<> cheers :)

[herve M]

Earl K,
2431 = titanium diaphragm
435al=2430 aluminium diapragm:homer:
hervé

[Earl K]

Earl K,
2431 = titanium diaphragm
435al=2430 aluminium diapragm:homer:
hervé


- Without the inclusion of question marks ( ??? ) / you have made 2 defacto statements ( which are both wrong ) .

- Both the 2431H & 2430H drivers have aluminum diaphragms. Of the two, the 2430 has a heavier diaphragm giving it a lower Fs and slightly less HF extension . The 435AL is a consumer derivative of the 2431H .
- Read up on the specification for these drivers ( as a start , go to the transducer library (http://www.audioheritage.org/vbulletin/forumdisplay.php?f=59) ) for some re-education .

<> cheers :)

[herve M]

:D sorry, the 2432h is titanium diaphragm , confusion

Million new reference !!!!!!!:banghead: 2430,2431,2432, 2406,2407,2408,2413,2414!!!!!!!!!!!!!!!!! :jawdrop:

:) my 2430h sound good. prime seller in 2002;)

[Mr. Widget]

The 435AL is a consumer derivative of the 2431H .
The 435AL diaphragm is also treated with aquaplas... I don't believe any of the pro drivers are.


Widget

[Fangio]

Caladois do you mean these, @ 3.200,– € all together?

http://cgi.ebay.fr/JBL-435-Be-045-Be-haut-parleur-a-compression-TAD_W0QQitemZ320436649025QQcmdZViewItemQQptZFR_LC_ TV_Son_Home_Cinema_HiFi_Enceintes?hash=item4a9b833 c41


...I am very happy at the moment.
So, what do you think you could improve then? Merely trying to add a voice of reason here.

[Robh3606]

I have done some measurements with aquaplassed 2431 and 2435's and from what I am seeing they may not be a simple driver swap. There is the efficiency and the top end rolloff are a bit different at least on an Array horn. The Titanium is in the 045Ti.

Rob:)

[caladois]

I just had a mp of Greg Timbers which coroborate your mind.
A simple swap is not possible, due to differents response of the drivers (both medium and HF).

Any way, I am very happy with what I have at the moment, and I do not want to tweak my originals cross over.

Thanks all for your interest.

Stephane

[caladois]

---

Caladois do you mean these, @ 3.200,– € all together?

http://cgi.ebay.fr/JBL-435-Be-045-Be-haut-parleur-a-compression-TAD_W0QQitemZ320436649025QQcmdZViewItemQQptZFR_LC_ TV_Son_Home_Cinema_HiFi_Enceintes?hash=item4a9b833 c41


So, what do you think you could improve then? Merely trying to add a voice of reason here.

Yes, but just for the 045be.
I imagine, this sale is now delete.

[andywin]

If I upgrade my 4338 with Be drivers, will it match ?

I have an opportunity on Be drivers, and I was thinking of replace the 435al and 045ti withe a full Be set up (435be + 045be) ?

I had a similar opportunity to "upgrade" my Array 1400's but the person selling the 045be's advised me I would probably have to tweak the crossovers or go active. So, like yourself I decided that as I am already very happy with the sound I'll leave well alone and besides I've got sort out a pair of matching cabinets formy BTH K10A's.