Re-coning newer drivers

[Vahe Sahakian]

I have a DIY 4350, my 2235's have been re-coned once using original JBL parts.
My question, going beyond 43xx and 44xx series, if I ever decide to get one of the newer JBL's, no Everest's thank you, but models with single 15" woofers, what happens if these require new surrounds? do the newer 15" woofers require periodic replacement of their fronts similar to the older versions and who would be qualified to do the job?
The reason for this question is partially based on what is happening to JBL, would there even be a JBL 10 years from now?

Vahe

[Ed Zeppeli]

Which woofers specifically do you have in mind? I don't think many of the modern JBL drivers are using foam any longer but could be wrong.

[audiomagnate]

I don't think you have to worry about refoaming anything in the future. Do a search for any speaker on eBay and all you get is refoam kits. There's too much profit incentive in selling something that costs pennies to make for $20 to $30 for this new cottage industry to ever go away. Now recone kits are another story, but the odds are you won't have to deal with that.

[Vahe Sahakian]

Which woofers specifically do you have in mind? I don't think many of the modern JBL drivers are using foam any longer but could be wrong.


In our area modern big JBL’s are not very popular and are hard to come by, what I am trying to do is to start doing my homework ahead of time just in case one shows up at fire sale price.
I am primarily interested in speakers with vertical orientation, K2, S4700, 4367/5 and the like with 15" driver, and also any reason to avoid a specific model.
I love my 3450 and it is not going anywhere, it has its strengths and weaknesses, I am strictly into classical, I am hoping that any one of these modern JBL would offer a somewhat more balanced and natural sound than my big 4 way when its called for.
The main problem of 4350 is its passive crossover (3107) and its inability to control the behavior of 2” compression driver at higher volumes which has a tendency to become overpowering.

Vahe

[Ed Zeppeli]

In our area modern big JBL’s are not very popular and are hard to come by, what I am trying to do is to start doing my homework ahead of time just in case one shows up at fire sale price.
I am primarily interested in speakers with vertical orientation, K2, S4700, 4367/5 and the like with 15" driver, and also any reason to avoid a specific model.


If any of those come up at firesale prices, get 'em. Also add the Array 1400 to your watch-list if a 14" woofer isn't too far out of your realm.

Good luck in your search.

[speakerdave]

In our area modern big JBL’s are not very popular and are hard to come by, what I am trying to do is to start doing my homework ahead of time just in case one shows up at fire sale price.
I am primarily interested in speakers with vertical orientation, K2, S4700, 4367/5 and the like with 15" driver, and also any reason to avoid a specific model.
I love my 3450 and it is not going anywhere, it has its strengths and weaknesses, I am strictly into classical, I am hoping that any one of these modern JBL would offer a somewhat more balanced and natural sound than my big 4 way when its called for.
The main problem of 4350 is its passive crossover (3107) and its inability to control the behavior of 2” compression driver at higher volumes which has a tendency to become overpowering.

Vahe

Forgive me if you already know this, but the 3107 has no low pass for the treble horn; it relies on the natural roll off (more like die off) at 9k or so of the 375/2440 diaphragm (aluminum with half-roll surround). If you are using a 376/2441 aluminum or a titanium diaphragm with the diamond wrinkle surround they both carry further into the HF and may be what is making things unpleasant.

[Vahe Sahakian]

Forgive me if you already know this, but the 3107 has no low pass for the treble horn; it relies on the natural roll off (more like die off) at 9k or so of the 375/2440 diaphragm (aluminum with half-roll surround). If you are using a 376/2441 aluminum or a titanium diaphragm with the diamond wrinkle surround they both carry further into the HF and may be what is making things unpleasant.


I have 2440's so that may be the problem

Vahe

[speakerdave]

I have 2440's so that may be the problem

Vahe

You mean you're not certain what's in them? Also, I forgot to mention, very old diaphragms can also sound bad due to metal fatigue.

And the capacitors in a crossover as old as the 3107, not as good as present day ones anyway, may have deteriorated as well, and that would affect the sound in the range of concern.

I mention these things because you may like those speakers a lot better performing at design level.

[Mr. Widget]

Also, I forgot to mention, very old diaphragms can also sound bad due to metal fatigue.
Personally I find the 4350 a bit squawky and did even when they were brand new, however if you like them at lower levels and find them too harsh when turned up, Dave may have nailed it.


Widget

[Vahe Sahakian]

You mean you're not certain what's in them? Also, I forgot to mention, very old diaphragms can also sound bad due to metal fatigue.

And the capacitors in a crossover as old as the 3107, not as good as present day ones anyway, may have deteriorated as well, and that would affect the sound in the range of concern.

I mention these things because you may like those speakers a lot better performing at design level.


Thanks for your tips.

On the 2" compression driver, they are 2440, purchased new in 1981 so yes they are old, they remained in the box until I assembled the system, I will contact the person who re-coned my 2235's, as far as i know he is the only person in our town that services JBL pro equipment, will find out what options are available for this compression driver.
Regarding 3107, i am in a slightly better shape, I have three of them, I can have the local JBL guy evaluate the spare and go from there.

Vahe

[Vahe Sahakian]

Personally I find the 4350 a bit squawky and did even when they were brand new, however if you like them at lower levels and find them too harsh when turned up, Dave may have nailed it.


I am in partial agreement with your comment and that is why I am trying to learn more about the new generation of JBL’s past 43xx and 44xx, so when one shows up I will know what to do .

One good thing about JBL’s from buyers perspective is that on the average audiophiles have a very low opinion of JBL’s, their recent large monitors are hard to find in US, are expensive to buy and near impossible to sell for what they are really worth, just type JBL on Fleebay and watch thousands of junk speakers pop up on your screen, that is how reputations are established and are near impossible to change.

Vahe