LE14a refoam question

[jimbofish]

I've read through quite a few threads here about refoaming these LE14a's. Didn't seem to find anything definitive as to whether the surround should go on the front or back of the cone. Seems like it works ok either way.

The new surrounds won't completely cover the area where the old foam is attached and it seems like it would be extremely unlikely that I could get all the old brown glue off without damaging the Aquaplas on the front of the cone. I've trimmed all the old Lansalloy back to a nice smooth edge at the cone edge, but haven't tried to remove it any further. It looks quite nice with the new foam test-positioned on the back.

The new foam weighs 5grams... the roll part of the old surround, which came off intact, weighs 3 grams... I'd guess the complete old surround would have weighed at least 6 to 7 grams. So, leaving the inner part of the old surround would add 1 or 2 grams to the cone weight.

I'm wondering if anyone has left the Lansalloy partially on the front of the cone and glued the new foam surround to the back?

[gdwrench]

Really all you need to do is get as much of the old adhesive off the face of the cone that you can (scraping with your thumbnail?) and gently rubbing it off, and adhere the new surround to that surface covering up the old surround remnants.Should turn out great.I know it does when I do it ;)

[jimbofish]

With a normal cone and surround, I'd agree with you. But these are a whole different animal. The old surround doesn't fall apart, it gets hard, and the glue is brown on a white cone. The white Aquaplas coating is pretty delicate... I used a q-tip dampened in acetone to get some duct tape adhesive off and it went right through to the black underneath.:crying:

As I said, the new foam won't cover it all.:crying:

[brutal]

I posted quite an extensive writeup here (http://www.audioheritage.org/vbulletin/showthread.php?469-Resurround-Step-by-step&p=197788&viewfull=1#post197788) on how I removed the Lansalloy. As for any JBL driver, the general consensus is "as the factory did them," no different for the LE14A. MEK is a little better at slow dissolving the glue than straight acetone. Too much of either and you risk soaking the aquaplas/cone. You want just enough to dampen the Lansalloy so you can peel it.

[gdwrench]

With a normal cone and surround, I'd agree with you. But these are a whole different animal. The old surround doesn't fall apart, it gets hard, and the glue is brown on a white cone. The white Aquaplas coating is pretty delicate... I used a q-tip dampened in acetone to get some duct tape adhesive off and it went right through to the black underneath.:crying:

As I said, the new foam won't cover it all.:crying: Yes you are correct,I was thinking of different cone and adhesive alltogether.I have yet too try to takle a cone like what you have there :confused: . Maybe one day I will get the challenge and be back here for refference ;)

[jimbofish]

I posted quite an extensive writeup here (http://www.audioheritage.org/vbulletin/showthread.php?469-Resurround-Step-by-step&p=197788&viewfull=1#post197788) on how I removed the Lansalloy. As for any JBL driver, the general consensus is "as the factory did them," no different for the LE14A. MEK is a little better at slow dissolving the glue than straight acetone. Too much of either and you risk soaking the aquaplas/cone. You want just enough to dampen the Lansalloy so you can peel it.

Yes, that was one of the threads I'd looked at. They look like new.

My surrounds are slightly over size in OD for the frame and I don't think the ID will cover the area where the old glue was on the cone... at least 1/8"-3/16" will still show. I can't imagine that hard, brown glue will come up completely with out damaging the white where it will show. Guess I'll have to get some mek and give that a try.

Does the mek soak right through the old surround to the glue or did you have to cut most of it off first? The acetone didn't seem to do much except wet the surface of the old foam, but it sure took the Aquaplas off easily.

[brutal]

Yes, that was one of the threads I'd looked at. They look like new.

My surrounds are slightly over size in OD for the frame and I don't think the ID will cover the area where the old glue was on the cone... at least 1/8"-3/16" will still show. I can't imagine that hard, brown glue will come up completely with out damaging the white where it will show. Guess I'll have to get some mek and give that a try.

Does the mek soak right through the old surround to the glue or did you have to cut most of it off first? The acetone didn't seem to do much except wet the surface of the old foam, but it sure took the Aquaplas off easily.

MEK helps soften the Lansalloy and glue but the key is not to saturate it, but dampen it just enough for the glue to loosen its grip on the Aquaplas. If the Aquaplas gets wet, it WILL come off.

If you didn't get surrounds from Rick Cobb, you got the wrong ones. Mine fit perfectly in the basket and to the same ID as the old surround.

[jimbofish]

MEK helps soften the Lansalloy and glue but the key is not to saturate it, but dampen it just enough for the glue to loosen its grip on the Aquaplas. If the Aquaplas gets wet, it WILL come off.

If you didn't get surrounds from Rick Cobb, you got the wrong ones. Mine fit perfectly in the basket and to the same ID as the old surround.

So the goal is to get the old foam to release from the glue, leaving the glue on the cone? I tried a little MEK on pieces of the old surround roll... it does seem to make it much more pliable, almost like soft leather, but it doesn't seem to have any effect on the glue. The glue on these is dark brown, not yellow.

I did get them from Rick... they're close, but not exact.

Edit: Added some pics of the woofer and the surrounds. According to the number written on the bag, they're the ones he said would fit. Is there a way to get them to shrink?

[jimbofish]

Oddly, if I turn the surrounds over, they drop into the frame very nicely... :dont-know:

[brutal]

Whatever it takes to get the old Lansalloy off without lifting the Aquaplas from the cone.

Are the surrounds still like that when separated? I would unstack them and leave them site for a few more days. Is it unusually hot or cold where you are? Have you sent the photos to Rick and discussed it with him?

[pathfindermwd]

Since we are on the subject, I recently refoamed a pair of LE14's for my 240ti's. I have previously successfully refoamed 2214's, and reconed 2214's, I felt it was a pretty easy task. But these LE14's were much more difficult. It was a really tight fit. I was able to just rub the completely deteriorated foam off the backs of the cones, but...I could not get the foam to completely seat on the back of the cone when glueing. So it has less contact area than the originals. I think this might of had to do with some spyder sagging/memory.
I was a little worried about this, and thought that i should have gone back in and reglued it after everything else had set up. I would guess that the foam has at least the same surface contact as the foam to the frame though. But, I didn't want to overload the cone with alot of glue weight. They play fine, but I still worry about them a little. Additionally, I wonder if this loose foam flange hanging out back there could become a problem when vibrated. Any opinions on whether I should go back and try to get this foam on the back of the cone glued down better?

[jimbofish]

Whatever it takes to get the old Lansalloy off without lifting the Aquaplas from the cone.

Are the surrounds still like that when separated? I would unstack them and leave them site for a few more days. Is it unusually hot or cold where you are? Have you sent the photos to Rick and discussed it with him?

I managed to get most of the old stuff off. One speaker seemed to be much more sensitive to MEK loosening the Aquaplas, so on that one I ended up "fileting" it off without the MEK. They both came out about the same. There's no way the glue is going to come off without destroying the Aquaplas, but it's on solidly, so it's just going to have to remain. I just need to come up with something to tone down the edge that will be visible as shown in the last pic.

Yes, it looks the same with just a single one although a bit lower of course. I've left them sitting separately. The temp in the basement is pretty steady around 64-69 deg.

No I haven't mentioned it to Rick .

[jimbofish]

Got a reply from Rick Cobb... he's never had or heard of a problem like this. He'll take them back, but then what do I do? Re-coning is out of the question for me, cost-wise. I've got to figure a way to make them fit or just part them out and move on.

Right now I'm so frustrated with these, I think I'll put them back together and stash them for a while... before I start stabbing a screwdriver through the cones. :banghead:

[brutal]

Got a reply from Rick Cobb... he's never had or heard of a problem like this. He'll take them back, but then what do I do? Re-coning is out of the question for me, cost-wise. I've got to figure a way to make them fit or just part them out and move on.

Right now I'm so frustrated with these, I think I'll put them back together and stash them for a while... before I start stabbing a screwdriver through the cones. :banghead:


I would send them back and ask Rick to compare them to a selection of his stock, perhaps from another lot/batch. Whatever you end up doing, good luck.

[westend]

Got a reply from Rick Cobb... he's never had or heard of a problem like this. He'll take them back, but then what do I do? Re-coning is out of the question for me, cost-wise. I've got to figure a way to make them fit or just part them out and move on.

Right now I'm so frustrated with these, I think I'll put them back together and stash them for a while... before I start stabbing a screwdriver through the cones. :banghead:
Can you publish a few dimensions so comparisons can be made? I would think the inside diameter of the frame, the ouside diameter of the cone, and the outside and inside diameters of the surround would be a good start.
I wouldn't throw out the baby with the bathwater, just yet. As a last resort, you could cut the surround and overlap the cut edge for a fit. Not a factory deal but I've done it and it works.

[Robh3606]

I did get them from Rick... they're close, but not exact.

Edit: Added some pics of the woofer and the surrounds. According to the number written on the bag, they're the ones he said would fit. Is there a way to get them to shrink?

I have refoamed a couple of pairs and the earlier ones with aquaplas have the best fit with the surrounds inverted. That said I did my first pair with the surrounds glued on the back and the I left the aquaplas ring on the woofer. It was a tight fit but it worked out fine.

I think what makes them harder to fit is the surrounds are flat and don't have an angle and the Le-14 cones is thick from being coated on both sides. Even with a later pair that were originally foamed they were a bit of work getting a good fit to the back of the cone where the originals were mounted.

Rob:)

[Earl K]

Bummer ( & not good news for Rick C. )

Here are some foam dimensions from another supplier ! (http://cgi.ebay.com/JBL-L220-14-Woofer-15-Passive-Speaker-Repair-Kit-/160483748711?pt=Speakers_Subwoofers&hash=item255d93ab67) ( found via eBay ) .

( I have no clue if they're really correct / though their marketing blurb would suggest they are, fwiw )



We are a JBL authorized service center and use these parts everyday.
http://w.mawebcenters.com/static/website/76/76370/files/New%20Foam%20Dia/NewFoamDiaMed-1.jpg

14" Woofer Dimensions:


A - Outside diameter of the surround : 12.125"
B - Roll ends : 11.75"
C - Roll starts / O.D. of the cone : 11"
D - Inside diameter of the surround : 10.5"


15" Passive Radiator Dimensions:


A - Outside diameter of the surround : 14.75"
B - Roll ends : 13.5"
C - Roll starts / O.D. of the cone : 12.75"
D - Inside diameter of the surround : 12"



One thought ( because I can't quite see from the pictures ) ; have you already removed the black plastic trim ring ( snugged up against the metal frame / hiding the edge of the existing surround ) ?

It occupies a bit of space / maybe enough to suggest a bad fit ( if it's still in place ) .

regards <> Earl

[jimbofish]

I have refoamed a couple of pairs and the earlier ones with aquaplas have the best fit with the surrounds inverted. That said I did my first pair with the surrounds glued on the back and the I left the aquaplas ring on the woofer. It was a tight fit but it worked out fine.

I think what makes them harder to fit is the surrounds are flat and don't have an angle and the Le-14 cones is thick from being coated on both sides. Even with a later pair that were originally foamed they were a bit of work getting a good fit to the back of the cone where the originals were mounted.

Rob:)

That was my original plan and I think I should have just gone with it now as it would have looked better. After playing with these things for over a week I find myself in agreement with all that you've said.

[jimbofish]

Bummer ( & not good news for Rick C. )

Here are some foam dimensions from another supplier ! (http://cgi.ebay.com/JBL-L220-14-Woofer-15-Passive-Speaker-Repair-Kit-/160483748711?pt=Speakers_Subwoofers&hash=item255d93ab67) ( found via eBay ) .

( I have no clue if they're really correct / though their marketing blurb would suggest they are, fwiw )


14" Woofer Dimensions:


A - Outside diameter of the surround : 12.125"
B - Roll ends : 11.75"
C - Roll starts / O.D. of the cone : 11"
D - Inside diameter of the surround : 10.5"


One thought ( because I can't quite see from the pictures ) ; have you already removed the black plastic trim ring ( snugged up against the metal frame / hiding the edge of the existing surround ) ?

It occupies a bit of space / maybe enough to suggest a bad fit ( if it's still in place ) .

regards <> Earl

Yes, those are the same dimensions. I checked a third supplier who doesn't think his would be any different from Rick's. I doubt that there's anything wrong with the one's Rick sold me. That they fit fine inverted seems to confirm that they are the correct size.

I've come across some more info from some very respected speaker gurus that seem to confirm what I'm seeing. Seems the conventional methods have to be "adjusted" to work with these speakers.

BTW I did remove the rubber trim ring.

[jimbofish]

Can you publish a few dimensions so comparisons can be made? I would think the inside diameter of the frame, the ouside diameter of the cone, and the outside and inside diameters of the surround would be a good start.
I wouldn't throw out the baby with the bathwater, just yet. As a last resort, you could cut the surround and overlap the cut edge for a fit. Not a factory deal but I've done it and it works.

The frame is 12 1/8" and the cone is 11", which matches up with Rick's surrounds and the surround dimension in another post. I don't think there's any need to cut them, although the thought did cross my mind.:D

[brutal]

Yes, those are the same dimensions. I checked a third supplier who doesn't think his would be any different from Rick's. I doubt that there's anything wrong with the one's Rick sold me. That they fit fine inverted seems to confirm that they are the correct size.

I've come across some more info from some very respected speaker gurus that seem to confirm what I'm seeing. Seems the conventional methods have to be "adjusted" to work with these speakers.

BTW I did remove the rubber trim ring.

Has to be something odd with the angle of the surround when placed either way. Rick specifically told me not to use them inverted as they wouldn't "work right." I just don't get why you're having so much trouble with these. Has the frame and cone dia. been compared to any others? Have you tried to pull the cone in with a battery and place the surround?

Let me run down and measure mine...

[brutal]

Hard to tell with the retainer installed, but the frame is 12-1/16".

One thing I see wrong with the image you show is the LE14A must be a small roll - 3/8" not 1/2" or larger. If you have 1/2" roll, they're wrong.

I went back and reread my old post and noted the surround was actually a little smaller than the frame. Hmmm.

[jimbofish]

Well, they're done! Right now I'm just waiting for the second dust cap to dry before testing. I was shooting for getting at least one done and re-installed last week before we left for the weekend. My plans were waylayed on Thursday when the A/C drain on the furnace plugged and caused a minor flood in the basement. :(

AFAICT there was nothing wrong with these surrounds. After leaving them dry-fitted in position on the speaker, they seemed to re-form back to their proper shape after a few days, with only the slightest bit of excess bulge that was an easy fit. My best guess is that they "relaxed" for some reason... maybe excess heat somewhere along the line in shipping since it's been so hot lately? :dont-know:

I did end up gluing them in reverse, that is, frame first, then cone. I haven't done a ton of surrounds, but I can say these were by far the most challenging even if the surround was not an issue. The narrow rim on the basket, the odd gasket, the Aquaplas surface, the ribs at the edge of the cone... :banghead: In hindsight, I think my plan in the OP would have worked just as well and been a lot less work.

So, I'm off to test them and finally hear how they sound.

[Wagner]

Use MEK and cotton swabs to remove old surround and glue

Use Rick Cobb's surrounds; they are a PERFECT fit (unless he's changed them)

Rick's new surround will perfectly cover the glue line from the old and fall concentrically into the frame like they grew there

Attach the new foam surround to the FRONT of the cone, with the roll facing you

I asked the same questions, did mine and then 2 more pair the same

Perfect; the old brown glue will roll up like a rubber cement bugger after the correct amount of MEK and time has transpired

Rick Cobbs's LE14A surround foams fit so well it is very easy to glue it all up at once if you make use of his 30CPS set up disc

Actually, seems to go better that way, and you only have to wait for (1) drying spell

Take your time; the solution will reveal itself

Avoid paralysis via over analysis

Good luck (just noted you got one done)

Thomas

[Wagner]

I've read through quite a few threads here about refoaming these LE14a's. Didn't seem to find anything definitive as to whether the surround should go on the front or back of the cone. Seems like it works ok either way.

The new surrounds won't completely cover the area where the old foam is attached and it seems like it would be extremely unlikely that I could get all the old brown glue off without damaging the Aquaplas on the front of the cone. I've trimmed all the old Lansalloy back to a nice smooth edge at the cone edge, but haven't tried to remove it any further. It looks quite nice with the new foam test-positioned on the back.

The new foam weighs 5grams... the roll part of the old surround, which came off intact, weighs 3 grams... I'd guess the complete old surround would have weighed at least 6 to 7 grams. So, leaving the inner part of the old surround would add 1 or 2 grams to the cone weight.

I'm wondering if anyone has left the Lansalloy partially on the front of the cone and glued the new foam surround to the back?


Again, Rick Cobb's will if installed properly
(old removed properly as well)