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1audiohack
04-25-2016, 10:40 PM
Hi All!

I have in my office a pair of 4435's that were built in 08-1986. They are original and the surrounds lasted just a few months shy of 30 years. One of them just started to crack, yeah I know, terrible design, only 29.5 years of trouble free service.;)

I have never re-foamed a speaker, I have always just re-coned them but I had seen on the bay these butyl surrounds from Japan and I figured if anyone was going to get this right it would be them. What the hell? What have I to loose? If they don't behave I will just re-cone them anyway so I bought four.

The first thing I learned is that if you value your time, just re-cone!

I haven't taken pictures yet but the roll is slightly smaller than the JBL surround. It fits the cone perfectly but leaves a slightly wider flat between the outer edge of the roll and the front foam gasket. This may not be noticeable to the average person but most of us would see it.

Other than that? Pretty close to perfection.

71112

The graph curser numbers didn't display so here is the rundown:

17 Hz Fs is with the original surround removed, no surround at all.

21.6 Hz Fs is with the original failing surround.

24.0 Hz Fs is with the new butyl surround installed.

Because I didn't want to be without music at all I re-coned four 2235's to 2234's while I went through this experiment. I swept all four of them of course and the average Fs of four of them is 24.4 Hz.

I will get these back in their original homes tomorrow during lunch and see if I can hear any difference from the new ones going back to these.

All the best,
Barry.

4313B
04-26-2016, 05:09 AM
Interesting!


They are original and the surrounds lasted just a few months shy of 30 years. One of them just started to crack, yeah I know, terrible design, only 29.5 years of trouble free service.;)Maybe it is a desert thing... I've noticed that the environment has a large effect on when exactly the foam surrounds fail. I think it is quite interesting how we forgo alleged superior performance for functionality. Greg mentioned a couple years ago how fantastic lans-a-loy was from a performance perspective but it had no longevity, hence the foam surrounds of the 2231/2234/2235, etc.

As an aside, years ago I purchased a whole bunch of recone kits from JBL that all contained foam surrounds in a very advanced state of rot. I should have kept the photos. In any case, JBL ended up crediting me for the kits and they all ended up with Rick Cobb refoams. A few months later when I went to order a few more of these kits I was told that the remainder had been destroyed. I could have simply refoamed them.

Flodstroem
04-26-2016, 11:10 AM
I was told that the remainder had been destroyed.

Oh my god :banghead:

:007: :montyp: :bash: :biting: :shocking::jawdrop:

hsosdrum
04-26-2016, 01:34 PM
Interesting!

I've noticed that the environment has a large effect on when exactly the foam surrounds fail.

That's for sure. Here in smoggy L.A. they have a considerably shorter lifespan than in areas that are comparatively smog-free. The same is true for the rubber drive belts on turntables and cassette decks (remember those?). Butyl rubber surrounds seem to be relatively impervious, thankfully—I've had my rubber-surrounded HT speakers for 20 years with no apparent degradation.

Joseph Smith Jr
04-26-2016, 09:52 PM
I have never re-foamed a speaker, I have always just re-coned them but I had seen on the bay these butyl surrounds from Japan and I figured if anyone was going to get this right it would be them. What the hell? What have I to loose? If they don't behave I will just re-cone them anyway so I bought four.

The first thing I learned is that if you value your time, just re-cone!Barry.
I cannot imagine why on earth you would do such a thing to such beautiful drivers, makes not one iota of sense to me when the closest to the original you're going to get is readily avaluable and is of a known quantity as well as being supplied from a well established and known to be excellent vendor
Especially as you claim that you value your time

And who knows, with a quad of Rick's surrounds those bad boys might just meet or exceed specs, you never know, but regardless, definitely a heck of a lot less of a gamble involved and at least they'd look correct

Bizarre

Hope it all works out

1audiohack
04-26-2016, 10:59 PM
Hi Joseph;

This was an experiment, nothing more. I wasn't looking to save money or time, simply to try a surround made from a material that is widely used by JBL and many others. Normally I wouldn't even bother to re-foam these, I would do the most correct thing and buy new JBL C8R2235 cone kits and keep them all 100% JBL.

Meet or exceed factory specs? Being within a couple of Hertz Fs is plenty close to me.

The truth is that these 30 year old speakers as great as the are/were, have been absolutely eclipsed by the new large format JBL monitors. That's why they ended up in the office.

I have thought about gutting the crossovers, replacing the woofers with 2216's and making throats for the 2344's that would use an 1.5" throat driver like a 2451 or D2430K but your still left with a 35 year old horn and that would be a waste of an otherwise near pristine pair of 4435's.

It is likely that I will soon re-cone these anyway because I like things proper. If the re-cones last like these did I will be 84 when they get weak again and I doubt I will care much by then.

So here is the intended value in this experiment, there is for those who hate the foam thing, a butyl surround that performance matches the 2234/2235 stock surrounds. Cobbs not the only game on the planet. There is a good non foam option, not for purists maybe but these guys have butyl surrounds for many others as well.

All the best,
Barry.

Ian Mackenzie
04-27-2016, 04:34 AM
The T/L parameters have nothing to do with the suround,

The surround minimises reflections back into the cone and provides air tight seal and centres the cone. Nothing else. In modern drivers a foam surround is not considered part of the radiating area.

In pleated paper surrounds the surround may form part of the radiating area.

The Driver relies on the spider and the coil, mass and profile of the cone for the LF and mid band response and of course the gap and Vol of the enclosure.

Provided only the suround is rotted l would not use an after market reconsider kit as a solution.

Talk to your pro reconvert first. If a recone is all that is required then do that.

But I do not see by butyl would not work and it would be useful to do some real measurements and impedance plots

1audiohack
04-27-2016, 06:08 AM
Hello Ian;

Did you read the first post?

The impedance graph is one I took of the same 2234 with the old surround, then no surround, and finally with the new surround. Although I didn't post them all, I measured all four in the same way. The suround does affect the Small signal Fs as is shown.

I also measured the four 2234's that I just re-coned with new JBL C8R2235 kits (with the mass rings left out) as a comparison.

My best,
Barry.

Ian Mackenzie
04-27-2016, 07:02 AM
I understand but what is the fs if a run in stock 2234.

According to JBL the Fs of a 2234 is 23 Hz, the 2235 is 20 Hz.
The Qts is .22, the Qms is 2.0

I am not discounting your measurements , obviously no surround is going make a difference. That is not what l meant .

If the butyl is really Stiff because it's new it might make a relative difference but your measurement is 24Hz. Compared to 23 Hz that is fuck all difference in production so l would not get too excited about that.

I am talking relative differences of surround types.

The effect of a different surround is more noticeable in the midrange than the bass.

What l am trying to explain is that the compliance of the spider (QMS)and the mms of the cone sets up driver in a working box along with the electrical QES.

The QTS or total Q is a lumped parameter based on half a dozen other parameters.

If the FS is up or down a bit it is normally compensated by another related parameter and you end up with the same Response in a enclosure.

James Bullock discussed this in his book Bullock on boxes Which is very detailed study of bass reflex designs and the impact of variation in T/L on box tuning.

Losses QL (box losses )have a bigger impact than small variation is FS.

But if you can do it reliably measuring the QTS is a great way to optimise a design.

Joseph Smith Jr
04-27-2016, 07:21 AM
This was an experiment, nothing more.
Cobbs not the only game on the planet. There is a good non foam option, not for purists maybe but these guys have butyl surrounds for many others as well.
All the best,
Barry.
I realize that, and to be honest, it's your business. But in my view, it is a waste of time and a mistake to experiment with a part not considered as part of the original design, so completely different in so many ways when there is one that's pretty darn close, if not possibly an exact match to what was called for by the designers of the driver and is readily available

And it takes the same amount of time to install either one, not to mention the hit you may take if you decided to sell them for whatever reason if ever

Outer compliance does make a difference in driver behavior, especially after you have some hours put on them

The unanswered variables, the "what ifs" would drive me nuts, but that's just me unless you do one with rubber and the other with foam and then take your measurements and compare behaviors then you'd know something for sure relatively speaking especially after you have so hours on them

And you are right, Rick's not the only game in town when it comes to foam edges, but based on experience, he definitely is the best game in town when it comes to coming even close to selling a product that is in the same ball park with what JBL used originally. Good example of that is what he sells to replace Lans-a-loy surrounds, they exceed even the parameters as defined when the drivers and the Lans-a-loy were new! And the fit of every surround I have ever bought from him, quite a few, is second to none, ID", OD", roll width and compliance

I have tried more than a few of the other vendors and nothing comes close, some were almost close, as in close enough to function but there was always some compromise either in material, appearance or fit ergo my loyalty to Rick's product

Good luck and I hope you results make you happy

Best wishes
Joe

JeffW
04-27-2016, 07:23 AM
I cannot imagine why on earth you would do such a thing to such beautiful drivers, makes not one iota of sense to me when the closest to the original you're going to get is readily avaluable and is of a known quantity as well as being supplied from a well established and known to be excellent vendor
Especially as you claim that you value your time

And who knows, with a quad of Rick's surrounds those bad boys might just meet or exceed specs, you never know, but regardless, definitely a heck of a lot less of a gamble involved and at least they'd look correct

Bizarre

Hope it all works out


Man, they are just 2234s, not some rare and irreplaceable masterpieces. Recone kits are still available. You make it sound like he painted a butyl moustache on the Mona Lisa. JBL is moving away from foam surrounds in favor of rubber, I'm not sure any of their new production designs still use foam. He clearly stated it was an experiment, and he certainly has the skill and resources to perform an inexpensive experiment on some extremely common drivers.


Good example of that is what he sells to replace Lans-a-loy surround, they exceed even the parameters as defined when the drivers and the Lans-a-loy were new! And the fit of every surround I have ever bought from him, quite a few, is second to none, ID", OD", roll width and compliance



Wait - now you are advocating replacing surrounds with something other than what JBL used?

Ian Mackenzie
04-27-2016, 07:37 AM
Storm in a tea cup!

I have to say when a foam surround starts to go it's very annoying.

I am in favour of challenging the convention.

Ian Mackenzie
04-27-2016, 07:44 AM
What interesting is the 2235h found its way (and the 2235 recone ) into many 2231 based boxes and no one gave a rats about the specs (16 Hz versus 20 Hz)just bolt it in and let it go. Ie the 4343.

But most people agreed the 2235 sounded a bit different.

4313B
04-27-2016, 08:52 AM
Strangely I ended up with J.M's cloth surrounds on all my LF transducers (2216Nd and 1501AL-2). Full circle. Cloth - Lans-a-Loy - Foam - Rubber - Cloth - The End.

1audiohack
04-27-2016, 10:35 AM
This was meant to just share some discovery, at my expense.

I assumed there would be some conversation about it and I welcome that. Criticism does not offend me, at all.

I have more measurements including the new 2234's and I can sweep them again now that they have had a month of play while I re edged the originals and see if they have changed although I doubt it as they don't get loud often or long in the office.

I also get that Fs is a weak force when in a vented box and or driven with a constant voltage source.

As for the different surround types that 4313b mentioned, I had a discussion with JM and GT during my last visit to Northridge about the 1500Al verses the 1501-1Al and GT said the cloth accordion surround knocked down a mid band ripple about a dB. I know there is a cone fiber material difference as well but they really were sweating the small stuff and making the best driver possible.

The 2234-2235 (tel:2234-2235)'s don't knock me out and never have. I don't hate them but A 1501-1Al with an Fs of 19 so far outshines a 2235 that it is nearly comical.

I will post a few more measurments when I get a minute that are not so zoomed in, they will look a little more familliar. I will do better at the notation as well.

All the best,
Barry.

4313B
04-27-2016, 11:19 AM
Yeah, the rubber surround played hell on the crossover frequency. It was pretty goofy actually. There was a way to get rid of it with a very narrow notch filter but the notch filter was too darn expensive. Going active solved the entire problem. :D

srm51555
04-27-2016, 11:34 AM
Man, they are just 2234s, not some rare and irreplaceable masterpieces. Recone kits are still available. You make it sound like he painted a butyl moustache on the Mona Lisa. JBL is moving away from foam surrounds in favor of rubber, I'm not sure any of their new production designs still use foam. He clearly stated it was an experiment, and he certainly has the skill and resources to perform an inexpensive experiment on some extremely common drivers.


What he said


This was meant to just share some discovery, at my expense.

Thanks for sharing, unfortunately for me I decided last week I was done learning anything new :p. But honestly, this is how we learn and grow as a forum community.

Thanks,
Scott

Ian Mackenzie
04-27-2016, 04:15 PM
I will be barking up my 2216's on the weekend.

Cloth surrounds and cloth ears must work...lol

Ian Mackenzie
04-27-2016, 04:18 PM
Some light humour.

Apparently a cloth surround copes better with significant DC across the speaker!

mech986
04-28-2016, 01:20 AM
Hang on to the mass rings.

any pics of the completed drivers? And how do they sound in the cabinets?

1audiohack
05-06-2016, 08:00 PM
Hi Mech!

They sound indistinguishable from the originals up loud or soft.

This picture shows the worst reveal of the surround and foam gasket where the gasket is pulled back by the clamp. This is how they were. I re-attached the gaskets to in their original positions.

I also cut all the dust caps off and used the JBL alignment sleeve while replacing the surrounds hence the darker cap color.

I don't know if I will just leave them as is or re-cone them. The fact that they are not original does bother me.

If the roll was accurate I think I would leave them. In the end, these do work just fine. I consider the experiment a success.

All the best,
Barry.

71321

mech986
05-06-2016, 11:08 PM
Nice, they do look fine at least at first glance, and if they sound similar, then perhaps there's little discernible difference, at least in this application.

As for reconing them, how about swapping them for other frames? I've got a number of 2235H and 2231 to 2235H frames that would need reconing anyway. Seems a shame to replace already functioning cones/voice coils with new if they are working fine.

Mr. Widget
05-06-2016, 11:13 PM
I also cut all the dust caps off and...
The glue job on that dust cap is your work? It looks damned fine.

Nice job!


Widget

1audiohack
05-07-2016, 09:52 AM
Nice, they do look fine at least at first glance, and if they sound similar, then perhaps there's little discernible difference, at least in this application.

As for reconing them, how about swapping them for other frames? I've got a number of 2235H and 2231 to 2235H frames that would need reconing anyway. Seems a shame to replace already functioning cones/voice coils with new if they are working fine.


I agree. The baskets are original to these boxes and that means a lot to me. I could try to save the kits but,,, well I don't know if it is worth the time.

The second lesson I learned is that if the proper re-cone kit is available and you value your time, just re-cone!

If the new surrounds looked exactly proper I would be done, but it bugs me, just a little.

Barry.

1audiohack
05-07-2016, 10:06 AM
The glue job on that dust cap is your work? It looks damned fine.

Nice job!

Widget

It is thank you! :)

Some years ago I paid Edgewound a half a days shop rate for an education. There isn't much one can't figure out on ones own if they put their mind to it but a good teacher saves you time.

My technique has evolved a bit over time. LOCTITE #410 is the glue used with LOCTITE #712 accelerator applied FIRST! The 712 lasts only about 30 seconds so the 410 application has to be accomplished in fairly short order. The felt is inert and will not kick the 410 and if you apply the accelerator on top of the 410 you get a rougher surface, which I personally don't care for.

The reason for the long answer is that I intended on this thread being somewhat educational to anyone going down this road.

Thanks again W!

All the best,
Barry.

mech986
05-07-2016, 12:56 PM
Hey barry,

thanks for the reply. If you do decide to recone, and you could save the old cone/spider/coils without major damage, I'd love a shot at reusing them or at least using them for practice on my frames. Let me know if there's a way to work that out. I could try to make it worth your while to save them.

Good Luck with whatever you decide.

Bart

pos
05-07-2016, 04:32 PM
Very nice job Barry!

Have you tried measuring them gain after some aggressive break-in in an effort to lower Fs?


If the new surrounds looked exactly proper I would be done, but it bugs me, just a little.
They look fantastic, you should keep them.
Consider this as a personal improvement exercise: learn to let go ;)

1audiohack
05-07-2016, 09:13 PM
Hi Thomas!

I have not re-measured them yet.

It's hard to be mean to them, they get loud so fast so easily. I am currently driving them with one of the M2 project amps (I-TECH 5000 HD) and I can't even get the -20dB LED to ever even flicker before I am ready to run.

You are probably right, I should just leave them alone. I might be able to talk myself into it. :)

Hi Bart!

If I cut them out I will definitely try to save them for you.

All the best!

Barry.

JuniorJBL
05-07-2016, 09:40 PM
I'm with widget! Are you a machine Barry? :rotfl:

Excellent work my friend! :)

pos
05-08-2016, 03:51 AM
By the way, what is the status of the C8R2235?

1audiohack
05-08-2016, 06:36 AM
By the way, what is the status of the C8R2235?

As of this morning, 161 in stock. :)

Barry.

pos
05-08-2016, 08:39 AM
Just enough for your different systems :D

Mr. Widget
05-08-2016, 12:07 PM
Just enough for your different systems :D I think you missed counted… I think Barry will be at least eight pairs short. :banghead:


Widget

grumpy
05-08-2016, 12:28 PM
:rotfl:

Joseph Smith Jr
05-19-2016, 07:59 AM
Wait - now you are advocating replacing surrounds with something other than what JBL used?
Lans-a-loy was eventually classified as a factory defect by JBL and treated as such and ultimately abandoned altogether, so in this instance, yes

And I wasn't making a big deal out of it, only that it would only yield truly meaningful results if compared, side by side, to two drivers with new surrounds of both types, not one on it's way out versus the new rubber one

I have had more than a few re-edge jobs meet factory specs completely, so in my view why screw with a good thing? Especially after the OP also made it clear that he usually re-cones anyway as a matter of personal practice

Those rubber surrounds have been around for a long time, Part Express has been hawking them for years, or at least they were

All I am saying is that if I a going to spend the time, and time is something once spent it is gone, to patch a driver, I'm at least going to try and use the closest thing to an original or correct part, known quantity, as is possible

Might consider the switch for some really nice high quality or specialty fit automotive driver, but otherwise I don't see the point as an end user, manufacturer? Yeah

Either way though, I wasn't making that big a deal of it, just wouldn't do it myself unless someone like Greg Timbers gave me a specific part number and said "here, use these instead"

Joseph Smith Jr
05-19-2016, 08:03 AM
He clearly stated it was an experiment,
I got that part of it too

4313B
05-19-2016, 08:09 AM
The fact that they are not original does bother me.It would me too. But that damn foam! :banghead:
It was totally fine back then when we didn't know any better. :p
Lans-a-loy was an even better termination but we all know how that turned out. :rolleyes:

I finally solved this sticky wicket by selling all my 2234H's and 2235H's and using 2216Nd's and 1501AL-2's instead. It was amazing how liberating that was. :rotfl:

JuniorJBL
05-19-2016, 08:47 AM
It would me too. But that damn foam! :banghead:
It was totally fine back then when we didn't know any better. :p
Lans-a-loy was an even better termination but we all know how that turned out. :rolleyes:

I finally solved this sticky wicket by selling all my 2234H's and 2235H's and using 2216Nd's and 1501AL-2's instead. It was amazing how liberating that was. :rotfl:



:rotfl:

honkytonkwillie
05-21-2016, 02:00 AM
I finally solved this sticky wicket by selling all my 2234H's and 2235H's and using 2216Nd's and 1501AL-2's instead.

Forgive my naivete, but how close are those drivers to being drop-in replacements for the 2234H or 2235H? I've not found much information on them yet.

I ask, because a pair of 15" drivers is next on my list to acquire for a 4430 build.

srm51555
05-21-2016, 05:56 AM
Forgive my naivete, but how close are those drivers to being drop-in replacements for the 2234H or 2235H? I've not found much information on them yet.

I ask, because a pair of 15" drivers is next on my list to acquire for a 4430 build.

Hello Honkytonkwille,

The 2235 has a slightly bigger hole diameter and a higher DCR of 6 vs 5 than of the 2216nd. When I was looking to get a second pair of 2235's I found the cores and oem recones were about $750. A pair of new 2216nd could be purchased for little over 1K. I ended up getting the 2216's instead of them. If I was going to build a 4430 though I guess I would stick with the original design because I have no crossover design experience to integrate the 2216.


Good luck, Scott

ivica
05-21-2016, 11:22 AM
Forgive my naivete, but how close are those drivers to being drop-in replacements for the 2234H or 2235H? I've not found much information on them yet.

I ask, because a pair of 15" drivers is next on my list to acquire for a 4430 build.
Hello Honkytonkwille,

You can compare T/S parameters of any of the mentioned, but I think that 2235 and 2216 are very different type of drivers.
On my opinion 2216 is good mid-bass driver, or may be used in the bass horn loaded configuration, but 2235 is a kind of very good bass driver especially used in the bass-reflex box type. If using two bass driver then may be 2234 can be used too, as a kind of mutual coupling in such configuration would happen.
Talking about 1500AL family drivers, I think is another story. You can see its T/S parameters so can conclude possible application.
Using 2216, I would suggest to be used with sub-woofer combination. I have no idea which one to be used as sub, may be 2269, or some from the 'older school' such as 2245, 2240, even 2242.
If all that in mind, may be 2235 or 2234 (in pair) would be the most effective solution.

regards
ivica

Ed Zeppeli
05-21-2016, 01:29 PM
Hello Honkytonkwille,

The 2235 has a slightly bigger hole diameter and a higher DCR of 6 vs 5 than of the 2216nd. When I was looking to get a second pair of 2235's I found the cores and oem recones were about $750. A pair of new 2216nd could be purchased for little over 1K. I ended up getting the 2216's instead of them. If I was going to build a 4430 though I guess I would stick with the original design because I have no crossover design experience to integrate the 2216.


Good luck, Scott

Funny. I'm looking to upgrade my current mains from 4430 to a modular that includes a bass cabinet with SAM1HFs up top. I have a spare pair of 2235s but truly desire a 2216nd to supply the bottom end. In the interim, I have designed a cabinet that would perch the SAMs up top and be compatible with both 15" drivers. Do you know off-hand how much smaller the cut-out is for the 2216nd?


Hello Honkytonkwille,

You can compare T/S parameters of any of the mentioned, but I think that 2235 and 2216 are very different type of drivers.
On my opinion 2216 is good mid-bass driver, or may be used in the bass horn loaded configuration, but 2235 is a kind of very good bass driver especially used in the bass-reflex box type. If using two bass driver then may be 2234 can be used too, as a kind of mutual coupling in such configuration would happen.
Talking about 1500AL family drivers, I think is another story. You can see its T/S parameters so can conclude possible application.
Using 2216, I would suggest to be used with sub-woofer combination. I have no idea which one to be used as sub, may be 2269, or some from the 'older school' such as 2245, 2240, even 2242.
If all that in mind, may be 2235 or 2234 (in pair) would be the most effective solution.

regards
ivica

Interesting. Although I do have a 2242 sub I would certainly want my set-up to be able to handle the full musical range. Despite the M2 frequency response, why do you feel that the 2216nd couldn't handle the very bottom end well? My understanding is that it is quite responsive to EQ. I'm hoping to build some bottom cabinets that will serve both drivers with only a necessary adjustment in port dimensions....eventually.


Cheers,

Warren

ivica
05-22-2016, 08:13 AM
Funny. I'm looking to upgrade my current mains from 4430 to a modular that includes a bass cabinet with SAM1HFs up top. I have a spare pair of 2235s but truly desire a 2216nd to supply the bottom end. In the interim, I have designed a cabinet that would perch the SAMs up top and be compatible with both 15" drivers. Do you know off-hand how much smaller the cut-out is for the 2216nd?



Interesting. Although I do have a 2242 sub I would certainly want my set-up to be able to handle the full musical range. Despite the M2 frequency response, why do you feel that the 2216nd couldn't handle the very bottom end well? My understanding is that it is quite responsive to EQ. I'm hoping to build some bottom cabinets that will serve both drivers with only a necessary adjustment in port dimensions....eventually.


Cheers,

Warren

Hi,
It would be very interesting to show us the results after finishing your projects...
I think that 2242 can accept EQ too...

ivica

1audiohack
05-22-2016, 09:32 AM
I want to get a pair of 2216-1's as used in the 2367. JM said they use a slightly softer spider and have a slightly lower Fs compared to the standard 2216 but the number doesn't come up in pro so I came to a dead end that I haven't fought my way out of yet.

That would the the one to have I think, I would like to know for sure though. :)

Barry.

Ed Zeppeli
05-22-2016, 10:14 AM
I want to get a pair of 2216-1's as used in the 2367. JM said they use a slightly softer spider and have a slightly lower Fs compared to the standard 2216 but the number doesn't come up in pro so I came to a dead end that I haven't fought my way out of yet.

That would the the one to have I think, I would like to know for sure though. :)

Barry.

Yes, I remember reading about that here. It makes me wonder if, despite its different specs, it will become the suggested replacement or if the two versions will co-exist.

grumpy
05-22-2016, 03:30 PM
Tried ordering those (-1 version) from the folks in Florida quite awhile ago and got blank stares (not too surprising at the time).
If you eventually make some progress, please let me know :)

srm51555
05-23-2016, 06:55 AM
Funny. I'm looking to upgrade my current mains from 4430 to a modular that includes a bass cabinet with SAM1HFs up top. I have a spare pair of 2235s but truly desire a 2216nd to supply the bottom end. In the interim, I have designed a cabinet that would perch the SAMs up top and be compatible with both 15" drivers. Do you know off-hand how much smaller the cut-out is for the 2216nd?


For the 2216nd the mounting hole diameter is 13.78" and the 2235 is 13.96875" when front mounting. I've been waiting for someone to do the 2216/SAM1HF combination. Keep us updated if you do decide to do this.

Thanks,
Scott

Ed Zeppeli
05-23-2016, 08:19 AM
For the 2216nd the mounting hole diameter is 13.78" and the 2235 is 13.96875" when front mounting. I've been waiting for someone to do the 2216/SAM1HF combination. Keep us updated if you do decide to do this.

Thanks,
Scott

Thanks for the info. Seeing as how I'd like to recess the drivers (flush mount) the differing dimensions could make it difficult. That's been my hesitation all along. I may have to hold off until I have the 2216NDs in hand and build them then.

Either way, I'll definitely keep the board posted.

Cheers,

Warren

4313B
05-23-2016, 11:05 AM
tried ordering those (-1 version) from the folks in florida quite awhile ago and got blank stares (not too surprising at the time).
If you eventually make some progress, please let me know :)320-0045-002 = 2216Nd-1
Note that GT used a 5.0 cu ft (142 l) box tuned to 36 Hz for 4367
Compare to S4700 with 4.78 cu ft (135 l) tuned to 32 Hz for 320-0045-001 = 2216Nd = NLA

Ed Zeppeli
05-23-2016, 11:33 AM
320-0045-002 = 2216Nd-1
Note that GT used a 5.0 cu ft (142 l) box tuned to 36 Hz for 4367
Compare to S4700 with 4.78 cu ft (135 l) tuned to 32 Hz for 320-0045-001 = 2216Nd = NLA

Well, that answers a few questions right there.
Thanks

pos
05-23-2016, 12:08 PM
320-0045-001 = 2216Nd = NLA
:blink:

grumpy
05-23-2016, 05:45 PM
Note that GT used a 5.0 cu ft (142 l) box tuned to 36 Hz for 4367

thanks! ... P/n suffix kinda has a certain logic to it :)

Doctor_Electron
05-25-2016, 06:28 AM
Storm in a tea cup!

I have to say when a foam surround starts to go it's very annoying.

I am in favour of challenging the convention.

+1

Dealing with rotten foam surrounds sucks. I'm sure a company with the resources and technical excellence of JBL at the time when foam surrounds were implemented could have come up with a more excellent design.

I am more interested in longetivity than originality considering how many expensive JBL systems I've had to spend money on to repair after their rot-out. And re-foamed drivers are original? Not exactly.

The "convention" sucks.

Joseph Smith Jr
05-25-2016, 07:23 AM
+1

Dealing with rotten foam surrounds sucks. I'm sure a company with the resources and technical excellence of JBL at the time when foam surrounds were implemented could have come up with a more excellent design.

I am more interested in longetivity than originality considering how many expensive JBL systems I've had to spend money on to repair after their rot-out. And re-foamed drivers are original? Not exactly.

The "convention" sucks.
No more than having to replace worn out tires on a Rolls-Royce
Just part of the experience of owning machines that move and do stuff, parts of it are going to wear out or change eventually
Don't think anyone can stop that
You'd think that with all of the resources and technical excellence of the space program someone could make tires that never need replacing and that work just as well as the ones that do
I have tried off and on over the years to narrow things down to owning only systems that used either pleated paper or cloth surrounds
Ain't gonna, just never seems, to be able to happen
Even those change performance or degrade over time, just might not be able to see it
Maybe eventually someone will come up with a synthetic foam material that can last forever and at the same time provide the required compliance?

BMWCCA
05-25-2016, 05:24 PM
You'd think that with all of the resources and technical excellence of the space program someone could make tires that never need replacing and that work just as well as the ones that do
With tires, grip and longevity have an inverse relationship. Look at what a great job we did with space-shuttle heat-tile adhesive, or Morton-Thiokol o-ring seals on the boosters.

People who want a better handling vehicle will pay to replace sticky tires more often. Those who don't care, buy bricks warrantied for 90,000 miles. It mostly depends on whether you drive an appliance—or something more engaging. :dont-know:

JeffW
05-26-2016, 08:06 AM
Maybe eventually someone will come up with a synthetic foam material that can last forever and at the same time provide the required compliance?

I would imagine all foam materials used on surrounds are synthetic - what natural foams do we have? Sponges?

As for something that can last (nearly) forever with the required compliance, you might take a look at post #1 of this thread ;)


Look at what a great job we did with space-shuttle heat-tile adhesive, or Morton-Thiokol o-ring seals on the boosters.


Actually, the adhesive works pretty well considering what it has to endure - no shuttles were lost due to the adhesive failing. And the o-rings worked fine for all launches where they were used in their specified temperature range.

1audiohack
05-13-2017, 09:32 AM
All in a year I have learned that:

Anyone really can be the US president.

Anyone with enough money can buy JBL/Harman.

Butyl rubber surrounds can indeed work even though this experiment caused as much uproar as the above two combined!


I wanted to report that although it is just over a year later that I am absolutely delighted with these surrounds. I don't hear or measure any difference at all between the re-edged set and the re-coned set. With the Fs being within 1Hz of the original I believe these will be what I use going forward.

One point of clarification. On the first page I stated that the roll width was slightly narrower on the butyl replacements than the old JBL originals. This appeared to be the case with the failing 30 year old surrounds but they are identical to the surrounds on the JBL C8R2235 that I built to run while the original 2234's were out for repair.

Still a winner in my book.

All the best,
Barry.

RMC
05-15-2017, 07:30 PM
Hi Barry,

I'm glad you bring back this Thread from a year ago I had not seen before. Great idea to test an unconventional solution to a common problem. It gives us one more driver repair option to consider for foam rot. Plus, I'm in the process of re-foaming my 25 yo 2214H drivers, but instinctively purchased new foams specific for this driver, instead of generic foams "one model fits all 12 drivers".

The thought of using Butyl rubber surrounds never even crossed my mind. If it had, and supposing some were available for my drivers (which I don't know), I'm not sure I would have dared to use Butyl surrounds, since I also like my things proper as you say. But your experiment (measurements and listening tests) is quite interesting for me and could make me change my mind in the future as to what is "proper"... Specially considering I like to keep my things working for a long time and having to re-foam is a pain in the neck.

However, there remains in my mind a technical question which may not have been addressed in this Thread and that is the Vas T/S parameter JBL defines as " Volume of air having same acoustic compliance as driver suspension". Could that be modified, maybe extensively or not, by other foams or Butyl rubber surrounds ? Also, will the new suspension behave the same and allow similar cone travel ?

In D.B. Keele's formulas to design a vented-box, the minimum T/S parameters required are Fs (which you measured), Qts (which Ian commented on) and Vas (which may have fallen in between two chairs ?). That Vas used to determine Vb must be important since it belongs to the short list of required numbers.

That's the bugger I'm wondering about regarding new foams or Butyl rubber surrounds, both not being the original stuff. What happens to Vas in the "modified" driver and its impact on cabinet Vb, shouldn't that be considered ? Is it still appropriate ? Box tuning Fb still suitable ? Low frequency response same as before? I wish many members would comment on that issue, as I don't have a definite answer, but my impression is that some things may have changed and/or have to be changed to be optimal.

Your listening tests seem quite positive and that's a very good start, plus we know such a modified driver will still reproduce sound: maybe very well, acceptable or not so well in some cases, since parameters may not be optimal anymore. I have read in many Threads here positive comments from people who have re-foamed with other than original stuff (as is usually the case including mine), but I can't remember seeing one where the "client" isn't satisfied and explains why/what's wrong. That leaves me somewhat puzzled, must be because I assume they can't be all "homeruns" all the time...

BTW I don't recall you mentioning from whom you got the Japan Butyl rubber surrounds, other than mentioning Bay. I would imagine pricing to be much more expensive than equivalent foams ?

Thanks. Best regards,

Richard

RMC
06-03-2017, 04:43 PM
Since I have no intention of extending inappropriately, reviving nor stealing this thread, I will soon continue with the interesting info I have found on this matter, in my own Thread called "Hybrid Reconed Drivers..." in the Tech Help section, it also addressed re-foam jobs with other than original stuff.

The reason being, in my view there are still a number of important and outstanding issues for the driver re-foamers and to some extent for the speaker builders. See you soon guys in the "Hybrid" Thread.

BTW I'm surprised at some of the comments Barry received here like "you shouldn't have done that or why did you do this to a JBL driver" type of comments (judgements). Instead, I see this has a valuable and feasible opportunity (i.e. additional option) for the many re-foamers here, like me. I think we should be grateful for benefiting from this experiment for free ! He spent a lot of time installing, measuring and listening, some money too and could have kept his mouth shut while enjoying the music, but he rather decided to share the experiment and his results with us, up to a year later... Anyway, Thanks for all of us Barry.

Richard

1audiohack
06-03-2017, 10:14 PM
Hi Richard;

You can hijack away if you want to but a separate hybrid thread will be more fun.

The noise about modding drivers was expected by me to some extent, and I actually think it's funny. This was such a small sin compared to what I have done in the past. There is something mildly disturbing and yet perversely satisfying about say, pushing a hole saw through the roof of a brand new zero mile Porsche.

I don't know how many brand new cars we have cut up to make into racecars at this point. We got pretty good at it, we could completely shell out a brand new car in about five hours and have it on a trailer to be acid dipped. Don't missunderstand, we don't just destroy stuff for fun but in the end, it's just stuff.

I am looking forward to your thread and will try to find some of my own hybrid driver measurments.

All the best!
Barry.

MoD
04-22-2020, 03:39 AM
It looks that friend of a friend of mine, has two E130 or E140 baskets, and would trade them for some motorcycle part I have.

If we trade, I plan to recone them with 2234 recone kit. If I am making frankenwoofer it would be great to (in my opinion) to install rubber surround, something like one from the firt post of this topic. Is there anything like that for sale? Only I have find is this (an that one will not fit as far as I saw);

https://www.speakerworks.com/15A-inch-speaker-repair-kit-p/swk15arb.htm

Kay Pirinha
04-22-2020, 05:30 AM
Sorry, I can't answer your question. Anyway, I think this thread of mine (http://www.audioheritage.org/vbulletin/showthread.php?42155-E-140-8-recone-to-2235H-s&highlight=)might be of some interest for you, too.

Best regards!

1audiohack
04-22-2020, 07:12 AM
Here is a current link to where I bought mine. Currently they don’t list the 2234-2235 (tel:2234-2235) surrounds but they come back around in time. You can contact them to see when they will have them again.

2234 kits in E motor baskets are my favorite variation of this woofer.

All the best.

Barry.






https://www.ebay.com/itm/RUBBER-SURROUNDS-Re-Edge-Kit-for-JBL-10-Woofers-Mid-Bass-LE10-LE111-2121-2122/282593256765?hash=item41cbdee53d:g:Ge0AAOSwiOFZOga r (https://www.ebay.com/itm/RUBBER-SURROUNDS-Re-Edge-Kit-for-JBL-10-Woofers-Mid-Bass-LE10-LE111-2121-2122/282593256765?hash=item41cbdee53d:g:Ge0AAOSwiOFZOga r)

Kay Pirinha
04-22-2020, 11:52 AM
Sorry, not exactly on topic, but definitely related: It is hard to imagine for me how a refoam or re-surround is done in JBL woofers where the cone is glued to the front of the surround instead of it's backside :confused:.

Best regards!

Flodstroem
04-23-2020, 03:01 PM
Sorry, not exactly on topic, but definitely related: It is hard to imagine for me how a refoam or re-surround is done in JBL woofers where the cone is glued to the front of the surround instead of it's backside :confused:.

Best regards!

Have you seen this thread:

http://www.audioheritage.org/vbulletin/showthread.php?469-Resurround-Step-by-step

Kay Pirinha
04-23-2020, 11:47 PM
Thanks, Flodstroem, I haven't seen this thread before ;).

I'm somewhat surprised to see that apparently there is no need to force the cone against the surround during the healing of the glue, which I had expected. I've refoamed some speakers (of lower value) where the surrounds are attached to the front of the cone and I've always applied gentle force during this process by means of a suitable dish or something like that.

Best regards!

Flodstroem
04-24-2020, 07:42 AM
Thanks, Flodstroem, I haven't seen this thread before ;).

I'm somewhat surprised to see that apparently there is no need to force the cone against the surround during the healing of the glue, which I had expected. I've refoamed some speakers (of lower value) where the surrounds are attached to the front of the cone and I've always applied gentle force during this process by means of a suitable dish or something like that.

Best regards!

Well, regarding the force, e.g. to press the surround against the cone, yes you need to do that if using the same white glue as in the instruction thread. You apply glue both to the surround and the cone and then gently press them together. You also must check that both parts has come together evenly all around the cone edge. Then after approx 5 min you go around it again and make som press around the cone edge. And you may have do it some more times until you feel they really has attached and do not come loose. Thats the reason for to use the white glue. Many re.foamer also use this glue for the outer lip of the surround for to be able to move the cone/VC sideways for to center it in the magnet. When come to gluing the outer lip I prefer to use the contact glue. If using the contact glue for to glue the outer lip of the surround you have to be pretty quick for to be able to move the cone so you dont get a vc scraping eg. you need center the cone/voice coil before the glue dries to much. When it has set then you cant move the cone any more. Many types of the foam surround do react to the contact glue and swell a lot so I dont recommend to use it. :blink: