Help Rebuilding an LE 14H-1

[bconline]

Hi everyone! This is my first post, but I have been reading Lansing Heritage for years.

I finally have a nice pair of vintage JBL's. One the LE 14H-1 woofers needs to be rebuilt. At first, I thought that it just needed refoaming. But the voicecoil only works intermittently (mostly open circuit), and it rubs no matter how I adjust the cone. So... I need to rebuild it.

AFAIK, there are no OEM rebuild kits available for the LE 14H-1. And the only aftermarket kit that I know of requires cutting down a larger cone, and the cone material is not the same (http://reconingspeakers.com/product/jbl-le14a-h-1-diy-aftermarket-recone-kit/).

Since this driver is part of a matched pair, so I want it to look and perform as original as possible. I have two Question for you reconing experts:

1) Does anyone know of a source for an OEM recone kit or parts for the LE 14H-1?

2) Is there any way to reuse the existing cone and dust cover, while installing a new voicecoil? For instance, will I be able to cut the original voicecoil off of the current cone. How would I then attach the new voicecoil to the cone. How would I align the new voicecoil without removing the dust cover from the original cone? How would I remove the old spider and install a new one?

I'd appreciate any advice that you can give me! Thanks in advance.

[bconline]

I solved my own problem! After reading some threads here, I guessed that the problem was the foam plug on the pole piece disintegrating and gumming up the voice coil. So I carefully cut off the dust cap to check. Sure enough, the foam had turned to a thick tar on the inside of the voicecoil, binding it in the gap.

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I cleaned the tar off. GooGone, soft cloth and thin sheets of plastic worked great. After re-gluing the dust cap with the proper black glue and replacing the foam, It's as good as new!

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My thanks to you experts here who led me to the solution. (BTW, it turns out that the "open circuit" was a red herring. My test leads were not connected reliably.)

Thanks again.

[Mr. Widget]

I cleaned the tar off. GooGone, soft cloth and thin sheets of plastic worked great. After re-gluing the dust cap with the proper black glue and replacing the foam, It's as good as new!Welcome to the Forum!

Question: Did you replace the foam with new foam? I could understand not wanting to, but I'm sure it was there for a reason. Damping the reflections off the pole piece I would assume.


Widget

[bconline]

Thanks for the welcome!

From reading on this forum, it seems that the purpose of the foam is to keep unwanted material out of the voice coil gap. But certainly failed at that!

Some people replaced it with new foam. Some replaced it with grill cloth material. Some said that it's not necessary. Having been bitten once, I was wary of putting anything in there that might disintegrate or come off in time. So I left it open. I might put a small patch of grill cloth material on the *outside* of the pole vent.

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[Mr. Widget]

If the foam's purpose was to act as a filter they certainly did screw up on that didn't they! ;)

I agree that an external covering would be most practical. I've seen a number of other woofers that are built that way.


Widget

[martin2395]

I had the same problem recently with a 2214H, it feels like it's the same kind of foam like JBL used in their comp. drivers.
It just turns into a sticky goo when you touch it...The cone was totally blocked but after a few hours on 30Hz and the woofer placed upside down so all particles would fall directly onto the dustcap I was able to shake shake it all out.

[bconline]

... a few hours on 30Hz and the woofer placed upside down so all particles would fall directly onto the dustcap...

I didn't think of that way of cleaning it out! I'll keep it in mind if there is a next time.

[martin2395]

I didn't think of that way of cleaning it out! I'll keep it in mind if there is a next time.

I did it only because the original 2214H has a thick layer of glue around the dustcap which (at least for me) would be difficult to remove without damage.

This method takes some time but it's quite effective, every time a particle will fall on the dustcap you will hear it bounce and then you can use a piece of masking tape to remove it.

[svollmer]

After re-gluing the dust cap with the proper black glue and replacing the foam, It's as good as new!

Can you share what is the proper black glue? I've always wanted to know in case I have to remove/replace a dust cap too.

[rdgrimes]

Can you share what is the proper black glue? I've always wanted to know in case I have to remove/replace a dust cap too.

I've gotten those type supplies from Orange Co, there's 3 types of glue:

http://www.speakerrepair.com/page/product/XL3.html

[Earl K]

Hmmmm,

Because any Browser's cache ( coupled with a websites Cookie placement system ) leads to false positives, here's my attempt at helping answer the glue question ( click the pics ) ;

http://www.speakerrepair.com/mm5/graphics/00000001/glue_4_343x343.jpg (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Product_Code=XL79)http://www.speakerrepair.com/mm5/graphics/00000001/glue_5_343x343.jpg (http://www.speakerrepair.com/page/product/XL3.html)


:)

[JeffW]

Ken at Upland mentioned that he substituted open weave cloth for the foam when he reconed my 2245s, the impression I got from him was that it was to keep debris out. Now whether or not that's what JBL intended, I don't know.Nice work on the LE14-1s.

[WDJ]

Is there a list of what drivers have internal foam filters/dampers?

[bconline]

Can you share what is the proper black glue? I've always wanted to know in case I have to remove/replace a dust cap too.

Sorry for the delay. Here's what I bought. http://www.simplyspeakers.com/speaker-repair-adhesive-mi-2000.html

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It worked really well. Probably the same glue as Orange County Speakers sells. But I could buy just the black glue from Simply Speakers for a little less money. They shipped very quickly.

[svollmer]

Sorry for the delay. Here's what I bought. http://www.simplyspeakers.com/speaker-repair-adhesive-mi-2000.html

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It worked really well. Probably the same glue as Orange County Speakers sells. But I could buy just the black glue from Simply Speakers for a little less money. They shipped very quickly.

Thanks very much! And thanks to you too Earl and RD.

[Earl K]

Is there a list of what drivers have internal foam filters/dampers?

- Not that I'm aware of ( JBL is certainly not going to admit their error by publishing a "replacement" list ) .

- FYI, almost every woofer made after @ 1979-1980 ( the @ time-period that JBL introduced it's ferrite-type, SFG magnet system ) has the internal foam filter.

- As a for instance , the newer le14H woofers have the internal foam filter while the older ( alnico type magnet ) used a ( plasticy ? ) bug-screen type ( internal filter ) .

:)

[WDJ]

My LE10Hs have the foam and it was a bit fun getting rid of it. I was able to get the big pieces out with a straw attached to a solder sucker for a vacuum source. Then took a borescope and went looking "inside" - didn't see anything so I gently pushed the cone in and never felt any sticking so pressed on.

I used a piece of "sheer" curtain material to replace the filter. Took a very small blower into a tube and measured its CFM with and without the fabric over the tube and saw no difference so figured it wouldn't affect the sound. The fabric can tolerate bright sun for years without disintegration so it will likely be able to handle a life spent in a dark cabinet.

Just wondering what else I have I need to worry about - figure my 2203H need a going over too!

enjoy!