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JBL L112 Refoam

madtech

madtech

Well-Known Member
JBL L110 Refoam Question

I have a set of JBL LE111A woofers that I'm refoaming for fellow AKer Cogsinister. Til this point I have always used shims in all of my refoam jobs with great results. The kit that I bought from Rick Cobb came with a 30hz test cd and no shims. The instructions seem easy enough but I'm debating about breaking out the shims regardless. I usually leave a flap on the dust cover and fold it back so I'm not worried about replacing it. Shims or no shims. That is the question. Thoughts?
 
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Yours may be different, but the 128H woofer in a JBL L112 has a piece of foam glued over the vent under the dust cap... the foam over time deteriorates and lodges between the cone and the piston(?).. it then turns to a gooey substance and causes a problem. That's a good argument to take a look under the dust cap- ( your title says L112)
 
Buttercup said:
Yours may be different, but the 128H woofer in a JBL L112 has a piece of foam glued over the vent under the dust cap... the foam over time deteriorates and lodges between the cone and the piston(?).. it then turns to a gooey substance and causes a problem. That's a good argument to take a look under the dust cap- ( your title says L112)
Click to expand...

The thread title should read L110 not L112.......
 
Done eight JBL units (mix of 8's, 10's & 12's) using the test tone alignment process. No problems to date.
 
Buttercup said:
Yours may be different, but the 128H woofer in a JBL L112 has a piece of foam glued over the vent under the dust cap... the foam over time deteriorates and lodges between the cone and the piston(?).. it then turns to a gooey substance and causes a problem. That's a good argument to take a look under the dust cap- ( your title says L112)
Click to expand...

If you play them loud enough, often enough, that foam plug gets blown right out over time. :D

ntrly

You're right about the potential of that plug to turn to ooze of course, but I've never had an issue with any of the 5 128H's here - 2 sets of L112 and spares.
 
Thanks guys. Yes, I did get the title wrong. The speakers are L110's and the woofers are JBL LE111A's. I think I'll give the 30hz cd a try. What's the worst thing that can happen....... lol
 
My first refoam job was JBL L110's using Rick Cobb's foam and tone CD. It worked great and i listen to them every day. Getting the original glue out of those grooves in the speaker basket was a real bite, though. You have my sympathies. :yes:
 
Hokieman said:
My first refoam job was JBL L110's using Rick Cobb's foam and tone CD. It worked great and i listen to them every day. Getting the original glue out of those grooves in the speaker basket was a real bite, though. You have my sympathies. :yes:
Click to expand...

Not so much with judicious application of M.E.K.

:D
 
Buttercup said:
Yours may be different, but the 128H woofer in a JBL L112 has a piece of foam glued over the vent under the dust cap... the foam over time deteriorates and lodges between the cone and the piston(?).. it then turns to a gooey substance and causes a problem. That's a good argument to take a look under the dust cap- ( your title says L112)
Click to expand...


One of my L112 woofers was seized, and after taking the dust cap off for a refoaming a few days ago, discovered that this was indeed the case. A bit of "Goof Off" and I was good to go.
 
I'm reviving this older thread because I have an issue with the foam vent covers on a set of JBL L112 woofers I'm in the process of refoaming.

My question is this. My foam vent covers are not totally rotten yet, but in the process of drying out. One has worked itself partially loose and is beginning to get crumbly. Obviously I'll remove them before gluing the dust caps back down. But should I put something in their place? I assume the foam was there to keep dust from working its way through the rear vent in the woofer. I was thinking of gluing a thin piece of porous cloth, possibly speaker grille cloth or cheesecloth, across this opening. Or is it best to simply leave the vent open with nothing over it?

I'm attaching some photos to illustrate this situation.

Thanks for your help!
 

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I've read where some guys have removed this foam altogether or shaped a new one and reinstalled. You can also use some types of packing foam to carve out a new one. Just make sure you vacuum out all the little bits of old foam before you glue the new one back in.
 
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