JBL 4348 - Horns 435AI repair info needed

[oldbrowndog]

Are those tinsel leads touching the ring? That could short them they don't look like they are coated there.

Rob

No they are not touching, i should have taken a shot from above, but no they are about 2-3mm away from the ring.

[Earl K]

@oldbrowndog,

Thanks for the pics.

All 3 magnets you've pictured are badly rusting ( the 2, 2435H are the worst and beyond help IMHO ).

The Japanese pricing is typical ( for them ). IOW, prices that are much higher than the rest of us would entertain paying.

Personally, I would simply buy a new pair of 2431H ( from the link that RobH previously provided ) , then install the larger ( interchangeable ) backcaps ( of your existing 435Al drivers ) and call it a day .

Click this pic for the link;





PS 1; Again, I feel these 2435H magnets are beyond redemption ( the Be diaphragms may well be salvageable////re-useable in a pair of new magnets >> maybe this is a job for Ian ) .
- This example's magnet has been rusting for a while .



PS 2; The "bad" 435Al might also possibly be salvageable >> if the gap can be cleaned of any debris in it and then possibly a new protective layer of thin epoxy laid into the bottom of the gap ( as a barrier to further migration of the magnet's cladding into the gap area ) .
- This would be a major "Science Experiment" ( due to the previous existence of ferrofluid there ) with the whole exercise possibly amounting to nothing more than a futile pain in the arse (with no real long term benefit ).

PS 3; In case it hasn't translated yet, all 4 models ( 435Be, 435Al, 2431h, + 2435h ) use a single type of interchangeable magnet. So that opens up your replacement options.

[oldbrowndog]

@oldbrowndog,

Thanks for the pics.

All 3 magnets you've pictured are badly rusting ( the 2, 2435H are the worst and beyond help IMHO ).

The Japanese pricing is typical ( for them ). IOW, prices that are much higher than the rest of us would entertain paying.

Personally, I would simply buy a new pair of 2431H ( from the link that RobH previously provided ) , then install the larger ( interchangeable ) backcaps ( of your existing 435Al drivers ) and call it a day .

PS 2; The "bad" 435Al might also possibly be salvageable >> if the gap can be cleaned of any debris in it and then possibly a new protective layer of thin epoxy laid into the bottom of the gap ( as a barrier to further migration of the magnet's cladding into the gap area ) .
- This would be a major "Science Experiment" ( due to the previous existence of ferrofluid there ) with the whole exercise possibly amounting to nothing more than a futile pain in the arse (with no real long term benefit ).

PS 3; In case it hasn't translated yet, all 4 models ( 435Be, 435Al, 2431h, + 2435h ) use a single type of interchangeable magnet. So that opens up your replacement options.

Thanks Earl, great and very useful info, seems like a feasible option to buy the 2431 and use that in its place, assuming you are 100% that this is the correct option for the 435AL?
I want to be doubly sure as this thread mentions the matching model is actually the 2430, but it could be incorrect?
The post is from 'vintage tubes' about 2/3 down the page & regarding the 4348 speaker, reads:

The bass driver is the new 1500Fe which uses the same basket as the 1500AL with a ferrite motor. Midbass is handled by the 10" pro 2251J which uses a differential drive motor. The midrange compression driver is the 435AL which is a consumer conversion of the 2430. This is the same motor as the 2435/435Be but uses an aluminum diaphragm instead of beryllium. The acoustic lens is gone, replaced by a small biradial horn. The UHF is the same 045Be from the S9800."

https://www.audioaficionado.org/archive/index.php/t-5637.html

Just want to be extra sure as if i go down this path and get the wrong driver im back to square one..

Assuming one of them is the correct model i would also assume:
1. no modifications to the crossover needed whatsoever?
2. how do u think the sound might differ from the 435AL?

[Earl K]

Sorry oldbrowndog .

I'm not 100% sure of anything ( regarding the "Plug-And-Play" substitution of 2431h drivers for your 435Al ).

It's really all just best guess since I don't own any variants of the 435 series ( 435Be or 435Al ) .

You'll need to continue to research this ( and hopefully others who have had those 435 drivers will offer-up their opinions and experiences so that you can move forward ).

[oldbrowndog]

Sorry oldbrowndog .

I'm not 100% sure of anything ( regarding the "Plug-And-Play" substitution of 2431h drivers for your 435Al ).

It's really all just best guess since I don't own any variants of the 435 series ( 435Be or 435Al ) .

You'll need to continue to research this ( and hopefully others who have had those 435 drivers will offer-up their opinions and experiences so that you can move forward ).

Ahh ok great good to know.
Yes its a bit of a mystery the old 4348.
I had hoped to simply buy another 435AL and not need to worry about all this but that hasn't proved easy, so its onto this search for info.
Many thanks for your input so far.

[Robh3606]

Are there any JBL Synthesis dealers in Australia?? The SAMHF is still current on the US site. The 435AL is used in that system. Maybe they could get you a spare driver?

Rob


https://www.jblsynthesis.com/product...r-oudspeakers/

[Ian Mackenzie]

Yes.

Generally they only support product sold under warranty in Australia.

However it’s worth a shot.

PS. The problem is not selling it but obtaining the product. The installer market is quite strong here. For a while JBL weren’t able to supply…like 2 years so dealers went to other brands.

[oldbrowndog]

Are there any JBL Synthesis dealers in Australia?? The SAMHF is still current on the US site. The 435AL is used in that system. Maybe they could get you a spare driver?

Rob


https://www.jblsynthesis.com/product...r-oudspeakers/

Wow, now thats a good lead, i had no idea they were still in production, you'd think they'd be able to spare one if that were the case for such a great speaker like the 4348.
but then..... anyway let you know thanks.

[Mr. Widget]

Are there any JBL Synthesis dealers in Australia?? The SAMHF is still current on the US site. The 435AL is used in that system. Maybe they could get you a spare driver?

Yes, the SAMHF still shows up on my dealer list... and if JBL were like any quality business who cared about their customers I'd say they must have stock for repairs. But, JBL has shown us over the years that they have chosen to take a different path.

It is certainly worth a shot though.


Widget

[oldbrowndog]

Yes, the SAMHF still shows up on my dealer list... and if JBL were like any quality business who cared about their customers I'd say they must have stock for repairs. But, JBL has shown us over the years that they have chosen to take a different path.

It is certainly worth a shot though.


Widget

Well your right about them not being very helpful.. Tried contacting them to no avail.
I did notice the model in the SAM1HF seems to be a 435AL-1 which may well differ from the 435AL?
Which puts me back in a similar position to finding a correct match for the 4348 in any case.

[Ian Mackenzie]

Just in

From a LHS member in Europe:

“Greg Timbers told me for few years ago at you can use 435Al-1 instead of 435Al in 4348 and 4338. 435Al-1 are smoother than 435Al because of the Aquaplas coated diaphragm.
435Al and 2431 have the same diaphgram only different back cap.@

[Earl K]

Just in

From a LHS member in Europe:

“Greg Timbers told me for few years ago at you can use 435Al-1 instead of 435Al in 4348 and 4338. 435Al-1 are smoother than 435Al because of the Aquaplas coated diaphragm.
435Al and 2431 have the same diaphgram only different back cap.@

@Ian,

That's interesting.

Who's words are you quoting ?

So the 435Al doesn't have an aquaplased diaphragm ? I assumed it did.

Oldbrowndog ought to remove his non-working one to confirm the lack of aquaplas.

[Robh3606]

Well that is certainly good news as the 2431's diaphragms are readily available. Looking back at the pictures I don't see aguaplas on the dead diaphragm. It should look flat dark grey almost flat black. That means he can just order a 2431 and switch back caps.

Rob

[oldbrowndog]

Just in

From a LHS member in Europe:

“Greg Timbers told me for few years ago at you can use 435Al-1 instead of 435Al in 4348 and 4338. 435Al-1 are smoother than 435Al because of the Aquaplas coated diaphragm.
435Al and 2431 have the same diaphgram only different back cap.@

Thanks Ian, well if Greg said it was so i think thats good enough verification. The question then remains do i search out 2 x 435AL-1 from JBL synthesis for matching mid horns.. Or just buy the 2431 & use it alongside the working 435AL i have... (I inferred that both the magnet & diaphragm in the 2431 exactly match the 435AL?)

What do you think would be the best solution?

[Ian Mackenzie]

I will see if l can get hold of a Greg and ask him.

Will email you when l have an update.

I should have done that in the first place rather than see it turn into a soap opera..Lol