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JBL L300/136a Help


I said, "And the 130A is a deeper basket/coil area"

You said "in a deep gap."

So you support what I said 130A is a deeper basket/coil area. OK...

"The difference between the 130A(2220) and most the other 4" coil drivers is the motor. The motor has a .350" top plate/gap depth. The D130 has a .280" gap depth. the frames are identical."

Again, supports what I said 130A is a deeper basket/coil area. OK...

"The cones are identical."

Then why is a 130A cone on a D130 basket considered a "frankenwoofer?"

And I know the "clank" I heard was the cone bottoming out on bass transients.
 
toddalin said:
I said, "And the 130A is a deeper basket/coil area"

You said "in a deep gap."

So you support what I said 130A is a deeper basket/coil area. OK...

"The difference between the 130A(2220) and most the other 4" coil drivers is the motor. The motor has a .350" top plate/gap depth. The D130 has a .280" gap depth. the frames are identical."

Again, supports what I said 130A is a deeper basket/coil area. OK...

"The cones are identical."

Then why is a 130A cone on a D130 basket considered a "frankenwoofer?"

And I know the "clank" I heard was the cone bottoming out on bass transients.
Click to expand...

No...I don't support anything you said.

A factory 130A recone kit...which would actually be C*R2220...is preassembled and should never be put in any frame model other than 130A/B or 2220A/B/H/J. Some Authorized JBL Service Agencies do it all the time...and it's flat out wrong. Can you figure out why? The voice coil will be actually hanging outside the gap if you put a 2220 kit in a D130. That's actually not a trivial detail, if you know what your doing...and care about it.
 
edgewound said:
No...I don't support anything you said.

A factory 130A recone kit...which would actually be C*R2220...is preassembled and should never be put in any frame model other than 130A/B or 2220A/B/H/J. Some Authorized JBL Service Agencies do it all the time...and it's flat out wrong. Can you figure out why? The voice coil will be actually hanging outside the gap if you put a 2220 kit in a D130. That's actually not a trivial detail, if you know what your doing...and care about it.
Click to expand...

So then, you are saying that if you lay a D130 next to a 130A, they will be the same height. It seems to me from past viewing that the "ring" between the basket and magnet is just a bit thicker on a 130A.
 
toddalin said:
So then, you are saying that if you lay a D130 next to a 130A, they will be the same height. It seems to me from past viewing that the "ring" between the basket and magnet is just a bit thicker on a 130A.
Click to expand...
Todd...

The frame itself is identical. The motors are different. That "ring" of which you speak is actually the top plate of the motor. It matches the thickness of the pole piece as well. These two pieces make up the gap depth. The D130 thickness is .280". The thickness of the 130A is .350". Because of this, if you set these two models next to each other...cone facing up, the 130A will be taller. They both share the same cone.
 
That's what I've been saying all along. The 130A would be taller meaning that it has to be deeper somewhere, and as you point out, it is at the gap.

If they share the same cone as you say, this included the voice coil because that's the way JBL sold them. So if they are the same "cone" then the 130A should have a bit more space in the gap to accomodate movement.

But then you point out that 130A recone is preassembled and, as we know, should not be used in a D130, so they are not the same "cone."
 
toddalin said:
That's what I've been saying all along. The 130A would be taller meaning that it has to be deeper somewhere, and as you point out, it is at the gap.

If they share the same cone as you say, this included the voice coil because that's the way JBL sold them. So if they are the same "cone" then the 130A should have a bit more space in the gap to accomodate movement.

But then you point out that 130A recone is preassembled and, as we know, should not be used in a D130, so they are not the same "cone."
Click to expand...

Todd...
You're not paying attention. I'm not sure you actually know how a speaker functions. Both D130 and 130A speakers from the early 60s forward have the same "space in the gap". The gap width is .057". The gap depth is different. D130 is .280", 130A is .350". The voice coil former for the 130A is longer than the D130 to place the voice coil windings down in the deeper gap.

The recone kit is comprised of three main elements: Cone/spider/voice coil. Both models share the same cone and spider. The voice coil is different, and when assembled for each model the depth of the overall moving assembly...recone kit...from bottom of the voice coil to the top of the cone is deeper for the 130A due to the longer voice coil former. Will each kit physically "fit" each others frames? Yes. Will they be correct? No, because the motors are different, and the coils will not be centered in the gaps linear center position....this is known as a "Frankenwoofer"...and it's wrong.

Now...all that said...a 136HS Synthesis subwoofer uses a 2220H frame/motor assembly, a 2226 cone coated on the rear with Aquaplas, a 2245 voice coil with a 2206/2226/2241 spider. Is it a "Frankenwoofer? No. Why? Because it's assembled to work as intended as a 136HS subwoofer. Will the "cone assembly" fit a 2205/2225/D130/D140/K130/K140/E130/E140 frame assembly? Yes. Will it work as intended? No. Why? because the voice coil will not be in the correct position.

Subwoof over at LHS did a fabulous disassembly of the 136HS here:
http://www.audioheritage.org/vbulletin/showthread.php?29626-136HS-stripped-naked

I can make a reproduction of this 136HS(ferrite 2220)...or 136AS(AlNiCo 130A/B, 2220A/B) subwoofer by using old unused frames that don't have a factory kit available. If one should have a stray standard 15" JBL frame and a stray 2245H motor they can be married together to make it work well, with a bit more powerful magnet.
 
JBL Tech notes.

The D/E140, 2234/2235 use a "long coil" in a "short gap"

The 2220/E145/(130A) uses a "short coil" in a "deep gap."

The D/E130 uses an "equal height" coil and gap.

It would seem to me that a short coil in a deep gap would have the least tendancy to "bottom out" during overexcursion.

http://warehousesound.com/r/jblTECHNOTE1-3A.pdf
 
toddalin said:
JBL Tech notes.

The D/E140, 2234/2235 use a "long coil" in a "short gap"

The 2220/130A uses a "short coil" in a "deep gap."

The D/E130 uses an "equal height" coil and gap.

It would seem to me that a short coil in a deep gap would have the least tendancy to "bottom out" during overexcursion.

http://warehousesound.com/r/jblTECHNOTE1-3A.pdf
Click to expand...

Most any speaker can "bottom out" during over excursion, but it's not always the voice coil former making contact with the back plate. Cone/spider joint can also make contact with the top plate. The mass ring is usually the culprit slamming into the top plate on drivers with a mass ring...and they can be knocked loose. The reason I prefer to mass load with dome with my True Reproduction kits. Another issue with the mass loading ring on 2235H is it's not enough mass to meet the Engineering Standard for moving mass. It comes up ~20 grams short.
 
Speaking of Jbl 15” woofers
Has any one here tried these new Butyl Rubber
surrounds listed on the Flea Baye ?
Seller is from Japan.
Also has Reproduction Unobtainable
Tannoy Diaphragms as well as Tannoy Foams
If this source has a proven Quality product, I hope they start making
Some other rare unobtainable JBLand altec items, 077's and Altec 3,000's Tweets
come to mind
 
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I wouldn't ever use a butyl surround in place of foam. The driver absolutely will not sound the same as it would with a foam surround.
Rubber surrounds are not age-proof. They might not fall apart like foam, but they do age in a negative way. They get stiffer with age, and bass performance diminishes. But, they still look good, even when they should be replaced.
 
tarior said:
I wouldn't ever use a butyl surround in place of foam. The driver absolutely will not sound the same as it would with a foam surround.
Rubber surrounds are not age-proof. They might not fall apart like foam, but they do age in a negative way. They get stiffer with age, and bass performance diminishes. But, they still look good, even when they should be replaced.
Click to expand...

I agree 100%. When rubber surrounds age, they get stiffer, in some cases eventually cracking. Many people think that their speakers are still performing to spec because they don't measure them, but they are not.

Once the rubber does need replacement, you usually can't remove the edge from the cone as completely, adding mass to the cone when you replace the surround. Plus as @tarior mentioned, if you're replacing foam with rubber you are changing the response of the driver with additional mass and reduced compliance.

I've had rubber surrounds that were original, and other than one set I decided to sell them when the rubber started to age. The ones I did keep I replaced with foam which turned out well, leaving the rubber edge to terminate more like the original surrounds, would like to have found original rubber for those to keep them original (but shaving that old rubber without flexing and damaging cones is quite a task). In this case new drivers were still available from the manufacturer so there was little to lose in trying.

Foam might not last forever, but it is the easiest to replace and the most compliant, and doesn't change properties as much vs temperature as rubber does.

If you're re-foaming 136A as in the OP, very good foam is available, and if the 136H complete OE cone kits are available as the C8R2235H, I don't know why anyone would try rubber unless he were able to measure the changes and wasn't worried about the results being bad enough to warrant reconing.
 
SaturationPt said:
I agree 100%. When rubber surrounds age, they get stiffer, in some cases eventually cracking. Many people think that their speakers are still performing to spec because they don't measure them, but they are not.

Once the rubber does need replacement, you usually can't remove the edge from the cone as completely, adding mass to the cone when you replace the surround. Plus as @tarior mentioned, if you're replacing foam with rubber you are changing the response of the driver with additional mass and reduced compliance.

I've had rubber surrounds that were original, and other than one set I decided to sell them when the rubber started to age. The ones I did keep I replaced with foam which turned out well, leaving the rubber edge to terminate more like the original surrounds, would like to have found original rubber for those to keep them original (but shaving that old rubber without flexing and damaging cones is quite a task).

Foam might not last forever, but it is the easiest to replace and the most compliant, and doesn't change properties as much vs temperature as rubber does.
Click to expand...

I see foam surrounds like an oil filter on an engine, easy enough to change, it's a consumable thing. Rubber as more mass and less damping too. Change the foam every 10 years and rotate the woofers and mids 180degrees.
 
A friend of mine that has more measurement equipment and experience than anybody else I know (raise your hands everybody who has a plane wave tube), and is also very good at re-cones/re-surrounds, used the rubber surrounds on some 2234 builds.

He noted that the roll was just a bit narrower than the worn out foam surround, but the drivers measured fine (basically perfect, within 1Hz Fs) with the rubber surrounds and later that the width of the surround was the same as a new set that came on some C8R2235 kits.

As expected, critics poured from the woodwork over his choice but they likely didn't realize just how many JBL drivers/systems he has. Putting rubber surrounds on the 4435s (they are his office system speakers, not front and center of his main system) was, as he repeatedly noted, just an experiment. He also has a JBL Pro account and can order direct, and had direct contact with JBL transducer engineers before Harman let them go.

http://www.audioheritage.org/vbulle...nds-from-Japan&p=390685&viewfull=1#post390685
 
That LH post was excellent, and in the end the guy that used the butyl surrounds left them in and could not hear any difference.
 
So...JBL has gone full circle and back to cloth surrounds. Gee...I wonder why?

C8R2235 is also on the 'kill list". Availability of kits coming out of Mexico is extremely limited. Currently, there are 25 kits "scheduled" to be delivered by April 26. My last order of C8R128H was cancelled by Harman with no explanation of future availability....probably because Samsung has no interest in stocking parts anymore for legacy products.
 
Jeffery said:
A friend of mine that has more measurement equipment and experience than anybody else I know (raise your hands everybody who has a plane wave tube), and is also very good at re-cones/re-surrounds, used the rubber surrounds on some 2234 builds.

He noted that the roll was just a bit narrower than the worn out foam surround, but the drivers measured fine (basically perfect, within 1Hz Fs) with the rubber surrounds and later that the width of the surround was the same as a new set that came on some C8R2235 kits.

As expected, critics poured from the woodwork over his choice but they likely didn't realize just how many JBL drivers/systems he has. Putting rubber surrounds on the 4435s (they are his office system speakers, not front and center of his main system) was, as he repeatedly noted, just an experiment. He also has a JBL Pro account and can order direct, and had direct contact with JBL transducer engineers before Harman let them go.

http://www.audioheritage.org/vbulle...nds-from-Japan&p=390685&viewfull=1#post390685
Click to expand...

He came to my shop many years ago, and I taught him how to recone JBL drivers. He said I'd be good at porting heads the way I handled my die grinder.

He makes racing differentials for super high end off road racing trucks. Very fine gentleman...and supremely technically gifted.
 
Alobar said:
So as to diaphragm replacements on the LE85, I had a little accident a few years ago when I had one of the LE85's out. Bonehead move, was being so careful with not letting the screws get away from me, I didn't pay attention to the terminal and that being ferrous, put a little dent in the diaphragm.. :rant:

Anyway, while I couldn't hear any difference I tried to get a new one. The original JBL's were like gold, so I went with the Radian replacements for both. I installed the first one that replaced the dinged one, and then played them like that for a few weeks. Did some listening comparisons, switched to mono and used the balance to go back and forth. I couldn't tell any difference. Now both have the Radian's and they sound quite good. Since my L200's are not really collectables like the L300, I see no problem with this so long as they sound good. In many ways, I'm glad I have the 200's as I don't feel compelled to scrounge and spend big bucks to keep them original. And with those 2216Nd1's I'm sure the sq has not suffered a bit either..

I was unaware of the blue diaphragms on the 077's. I checked mine, yep blue. Hopefully I never have to mess with those!
View attachment 2159636
Click to expand...

+1 on dinging the coil on my Horne Diaphragm(was a hard lesson to learn but one definitely learned). Will definitely look for a radian replacement as I can’t find any originals anywhere.

Ok so now I’m finally getting close to making my L300 a reality. All’s I’m missing are the woofers. My dilemma is that those 136a woofers are just impossible to get and whenever they do turn up they’re either needing a recone and cost an arm and a leg. I was able to find some E140’s or 2225’s which I intend to use. (I was reading up on the thread Next is the L300 cabinets themselves. Which I intend to build to factory specs. Does anybody have the file for exact dimensions?!? Please and thanks. I did see it on eBay for 30$ but was hoping someone here would happen to have it. Thanks in advance and if anyone could chime in on which woofer would work best would be amazing
 
2235H is a good woofer for L300, it is the JBL recommended replacement for the original AlNiCo driver.

Not saying they won't also cost an arm and a leg though.
 
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