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oceanexplorer
03-06-2011, 10:47 AM
Hi All-

I have recently purchased a pair of L250's. :D The speakers just arrived on friday and since then I have been planning and beginning the process of getting them into as near original condition as possible.

The cabinets are in very good (but not perfect) shape, but a couple of the drivers need repair.

The LE14H-1's need (at least) to be re-foamed. The foam is deteriorating and broken around the edge of the driver; so I've purchased re-foam kits, and have started to take the old foam off one of the cones, but am not sure how to proceed, so I'd like some advice.

I have a picture of one of the drivers, as I received it, and a couple if pictures after beginning the re-foam process on the other driver. I've removed the old foam, and can see how the new foam will attach to the back of the cone, on the inside edge of the foam, to the outer edge of the cone. But I don't see how to attach the outer edge of the foam to the speaker frame and gasket.

Specifically, the frame of the transducer has a metal flange or face, with what appears to be a thin rubber ring around the inside edge of it (about 1/8 in. thick by 3/8 in. tall). Is this called the gasket? Do I need to remove this to put the foam underneath it and then glue it back? There is also a rubber gasket like material protruding out the back of the frame (4th photo with the terminal posts showing). I've heard that these transducers are notoriously difficult to get fixed, and in fact I've been told by two local speaker repair shops that they won't fix them period.

I feel like I'm in the deep end without my water wings...

Thanks in advance,

Jim

BMWCCA
03-06-2011, 11:06 AM
I feel like I'm in the deep end without my water wings...

It's a sticky (http://lmgtfy.com/?q=jbl+resurround+audioheritage).

rdgrimes
03-06-2011, 11:46 AM
Specifically, the frame of the transducer has a metal flange or face, with what appears to be a thin rubber ring around the inside edge of it (about 1/8 in. thick by 3/8 in. tall). Is this called the gasket? Do I need to remove this to put the foam underneath it and then glue it back? There is also a rubber gasket like material protruding out the back of the frame (4th photo with the terminal posts showing). I've heard that these transducers are notoriously difficult to get fixed, and in fact I've been told by two local speaker repair shops that they won't fix them period.

Jim
Yes, that little plastic ring is the "gasket". Look closely, there's a split in it in one spot. It's usually helpful to use an Exacto knife to separate the gasket from the flange, starting at that split. After doing the re-foam job you'll just glue it back in to hold down the new surround.

Be sure to remove all the old foam from the back of the cone, it usually just rubs off with your fingers.

brutal
03-06-2011, 11:55 AM
Where did you get the "kits" from?

The locals shops are full of it. LE14H-1's are worthy and certainly easy enough to refoam. Recone kits may still be available to authorized JBL repair centers.

The back rubber is just a frame-cabinet seal, leave it be.


Be sure to remove all the old foam from the back of the cone, it usually just rubs off with your fingers.

What doesn't come off manually can be removed with a Q-tip soaked in MEK. Use it sparingly and not so much that you wet the cone paper. Same goes for cleaning the front gasket ring and basket surface of old foam/glue. The new glue will stick to the old glue if left on, but any old foam must be removed.

oceanexplorer
03-06-2011, 12:25 PM
Thanks for the helpful posts (BMWCCA and rdgrimes), I think I have the correct info now...

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

oceanexplorer
03-06-2011, 12:35 PM
Where did you get the "kits" from?
:
The back rubber is just a frame-cabinet seal, leave it be.

What doesn't come off manually can be removed with a Q-tip soaked in MEK. Use it sparingly and not so much that you wet the cone paper. Same goes for cleaning the front gasket ring and basket surface of old foam/glue. The new glue will stick to the old glue if left on, but any old foam must be removed.


Orange County Speaker Repair - they said they were JBL original parts, not a knock-off, but how do you know?

OK, I'll leave the backs alone. I can see that now...

BMWCCA
03-06-2011, 01:05 PM
Orange County Speaker Repair - they said they were JBL original parts, not a knock-off, but how do you know?.

You know because there is no such thing as a original JBL part for just the surround. Though hopefully they're a reasonable alternative. Nothing against re-surrounding JBLs. I do it all the time. I just wish the sellers would tell the truth.

It would be nice if this weren't your first attempt at a resurround. What you're working on is a fine speaker that deserves to have it done correctly. Take your time and be careful. I hope you're not using a kit that has you cutting off the dust dome and replacing it? Search for "Rick Cobb" and you'll find an easier less-invasive method.

rdgrimes
03-06-2011, 03:19 PM
Orange County Speaker Repair - they said they were JBL original parts, not a knock-off, but how do you know?

OCS is completely reliable, and their foam kit is an exact fit. They come very close to self-aligning. I can think of may woofers that are far more difficult to do correctly, but given the high cost of replacing those monsters, be careful.

oceanexplorer
03-07-2011, 08:06 PM
Where did you get the "kits" from?

The locals shops are full of it. LE14H-1's are worthy and certainly easy enough to refoam. Recone kits may still be available to authorized JBL repair centers.

The back rubber is just a frame-cabinet seal, leave it be.



What doesn't come off manually can be removed with a Q-tip soaked in MEK. Use it sparingly and not so much that you wet the cone paper. Same goes for cleaning the front gasket ring and basket surface of old foam/glue. The new glue will stick to the old glue if left on, but any old foam must be removed.

Can I use acetone instead of MEK? I'm concerned about damaging or degrading the rubber gasket.

brutal
03-07-2011, 10:17 PM
Can I use acetone instead of MEK? I'm concerned about damaging or degrading the rubber gasket.

Acetone is much faster evap/drying than MEK. MEK works best to disolve the old foam and glue and give you time to work. That gasket is pretty durable hard plastic. Whatever you use - manual, Acetone, MEK - start slow, work a little at one time, and don't overdo it.

You should consider finding a $20 driver and $5 surround for a practice run. You'll quickly learn all the wrong things to do.

subwoof
03-09-2011, 05:03 AM
A little info for all of you "less invasive" types.

You should know that a piece of foam, same material and age as the rotted surround, covers the vent hole in the magnet *behind* the dust cap you are loathe to remove.

This will eventually dissolve into pieces and go into the gap. Nice and sticky. Then if you are lucky enough, the stuff will melt-harden, the coil will jam then overheat. Now you WILL need a total recone.

Take it to a speaker repair place that has done it many times, they will remove + replace the cap with a new one, replace the foam(s) and actually use the correct shim to make sure the coil is centered.

But it's the 600 dollar question isn't it??

maxwedge
03-09-2011, 08:35 PM
A little info for all of you "less invasive" types.

You should know that a piece of foam, same material and age as the rotted surround, covers the vent hole in the magnet *behind* the dust cap you are loathe to remove.

This will eventually dissolve into pieces and go into the gap. Nice and sticky. Then if you are lucky enough, the stuff will melt-harden, the coil will jam then overheat. Now you WILL need a total recone.

Take it to a speaker repair place that has done it many times, they will remove + replace the cap with a new one, replace the foam(s) and actually use the correct shim to make sure the coil is centered.

But it's the 600 dollar question isn't it??
A little off topic, as far as spk type, but I have some e120's with loose junk inside the magnet under the screen on the back. That's the same deal right? Foam gone bad?

brutal
03-10-2011, 07:08 AM
A little info for all of you "less invasive" types.

You should know that a piece of foam, same material and age as the rotted surround, covers the vent hole in the magnet *behind* the dust cap you are loathe to remove.

This will eventually dissolve into pieces and go into the gap. Nice and sticky. Then if you are lucky enough, the stuff will melt-harden, the coil will jam then overheat. Now you WILL need a total recone.

Take it to a speaker repair place that has done it many times, they will remove + replace the cap with a new one, replace the foam(s) and actually use the correct shim to make sure the coil is centered.

But it's the 600 dollar question isn't it??

While I don't disagree, I think because the foam plugs are subject to less UV exposure they don't deteriorate as quickly. I just reconed a 2245H that was obviously done (poorly) at least once before in it's life, yet the original foam cover that was in the early stages of deterioration remained, so it got removed and replaced. I think climate also has an affect on the rate of decay.

I wasn't uncomfortable doing all the 12" around here with RC kits and no dust cover cutting, I'm not so sure I would take the same chance with LE14H's when the time comes. Does anyone know if all the drivers had the foam plugs? I know the 128H has foam, the 122A-1 had mesh cloth.

Anyway, I think I've blown most of my foam out the back vent hole. :D

OC Speaker
03-10-2011, 12:41 PM
You know because there is no such thing as a original JBL part for just the surround. Though hopefully they're a reasonable alternative. Nothing against re-surrounding JBLs. I do it all the time. I just wish the sellers would tell the truth.

It would be nice if this weren't your first attempt at a resurround. What you're working on is a fine speaker that deserves to have it done correctly. Take your time and be careful. I hope you're not using a kit that has you cutting off the dust dome and replacing it? Search for "Rick Cobb" and you'll find an easier less-invasive method.

Just an FYI, we would never tell someone these surrounds came from JBL directly. They do not sell surrounds, just complete recone kits. We do tell people, however, that these surrounds are correct and match the original specs.

Also, as others have said, the rubber gasket on the front does need to be removed, and you will glue this back on after the new surround has been installed. These particular surrounds are pretty simple to install and you do not have to remove the dust caps.

Take care,
Eric Sunda
Orange County Speaker

BMWCCA
03-10-2011, 07:00 PM
Just an FYI, we would never tell someone these surrounds came from JBL directly. They do not sell surrounds, just complete recone kits. We do tell people, however, that these surrounds are correct and match the original specs.
I was only repeating what your customer said he was told. Maybe it was just what he wanted to hear?


Orange County Speaker Repair - they said they were JBL original parts, not a knock-off, but how do you know?

OC Speaker
03-11-2011, 09:36 AM
I was only repeating what your customer said he was told. Maybe it was just what he wanted to hear?

No worries, I just wanted to clear things up. :)

Thanks,
Eric