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SEAWOLF97
02-06-2012, 12:28 PM
.
I recently bought some 250Ti's that need refoaming ....purchased the Rick Cobb kit..

removed old foam and cleaned up basket and cone pretty well after removing the black plastic ring.
so I test fitted the foam ring ...its pretty tight against the basket channel , but there is maybe 1/32
gap between surround and cone.

I've always glued the surround to the cone FIRST and did centering adjustments on the next glueing to the frame ...this does not appear possible here ...I PMed a forum member who has done some of these and uses
OC rings , he does them in the same order that I've traditionally done the smaller ones.

to do THIS one correctly, should I be glueing to the basket frame FIRST and then centering on the step of
attaching the cone ?

I realize that as long as it works correctly, the order is less important, but I'd like to get forum advice before starting on an expensive driver..

thx.

Robh3606
02-06-2012, 12:50 PM
I've always glued the surround to the cone FIRST and did centering adjustments on the next glueing to the frame ...this does not appear possible here ...I PMed a forum member who has done some of these and uses
OC rings , he does them in the same order that I've traditionally done the smaller ones.


That's the way I always do it. Get it centered on the cone first and then use the "slop" on the frame. Problem is there is very little "slop" on those square frame drivers, I have done a couple of pairs and I had one driver that was extremely hard to center. Can you post some pictures not sure what you mean by the gap. Is the gap between the cone and the edge of the surround on the back of the driver??

Rob:)

SEAWOLF97
02-06-2012, 01:17 PM
Is the gap between the cone and the edge of the surround on the back of the driver??
Rob:)

when positioned with foam under the cone..the gap between the inside edge of the roll and outer edge of the cone ..it is the only place where I can see any possible adjustment , hopefully it needs none and can stay perfectly centered.

pathfindermwd
02-06-2012, 02:27 PM
when positioned with foam under the cone..the gap between the inside edge of the roll and outer edge of the cone ..it is the only place where I can see any possible adjustment , hopefully it needs none and can stay perfectly centered.

I guess I would start with the cone as well. I had lots of difficulty with my set. I could not get the surround to lay down on the back of the cone. I did it all at once and it was very nerve racking. Never did get it on the back of the cone perfectly. Are you going to use a test tone, or shims? I carefully cut the dust cap leaving just a little piece connecting it to the cone, then shim. They are a lot more difficult than the 2214's I have done a few times.

-Hope it goes well.

Amnes
02-08-2012, 09:01 AM
Seawolf can you post a pic of the dry fit?

SEAWOLF97
02-08-2012, 09:16 AM
Seawolf can you post a pic of the dry fit?

I rechecked the fit...the foam fits EXACTLY in the baskets ledge/groove/shelf and there is NO play room.

went to Google and found that others are doing it BACKWARDS , as I asked about ...so yesterday I glued the outer lip to basket FIRST and it is dry by today so now must use inner lip to make alignment adjustments. put on the black plastic ring at the same time and it seems to hold down the lip.


I did it all at once and it was very nerve racking.
-Hope it goes well.

have NEVER done it "all at once" ..has always been a 2 step proc for me.

doyall
02-09-2012, 07:48 PM
...so yesterday I glued the outer lip to basket FIRST and it is dry by today so now must use inner lip to make alignment adjustments. ...

How is it working out? Would you do it that way again? Did you do them both that way?

Curious as I have some LE14H-1's that I need to do.

SEAWOLF97
02-09-2012, 08:40 PM
How is it working out? Would you do it that way again? Did you do them both that way?

Curious as I have some LE14H-1's that I need to do.


first one came out fine ..yes, 2nd will be same proc.

doyall
02-10-2012, 04:33 AM
first one came out fine ..yes, 2nd will be same proc.

Did you use shims or test tone to align the voice coil? (Seems like it would be difficult to glue down the moving cone.)

SEAWOLF97
02-10-2012, 10:36 AM
Did you use shims or test tone to align the voice coil? (Seems like it would be difficult to glue down the moving cone.)
first ..some observations b4 I answer your question.

I knew the shelf/race/ridge on the basket that the outer foam lip glues to is small, but measured it to quantify ...
it is EXACTLY 1/8th inch wide
there is a black plastic ring that goes on top of that lip ..pretty flexible and tough but a bear to get the old glue off it.

heaviest, non flexible cone I've seen ...

very little room to get a finger between the cone & basket to remove old surround from rear of cone driver is rather heavy ...must be removed/inserted with cab on its back
the Rick Cobb kit is just fine, but I don't think he provided enough glue to do 2 fourteen inch drivers. luckily I stall have my own supply

shims ? NO .... tone ? NO ....
to answer your Q.
I shimmed on my very first driver that got refoamed (years ago) ...lots of chances to damage the face of the driver when removing dust cap ....have never even had a tone until I received this RC kit since lifetime refoam #2 (have most likely done near 200 so far) ..

I have used the "Yoda Method" ...."use the force" , "BE the foam/cone" etc. ...I center the cone by hand and then with equal pressure from both hands , work the cone in and out, then turn 90 degrees and repeat and turn another 90 and ...........until I am happy with alignment and then either clamp down or leave alone to dry. never have had a job go bad.

JuniorJBL
02-10-2012, 12:44 PM
I have done all of my -1's (4 pairs) myself. The first one I ever tried, had a rub so I then re-did the surround a second time. I did find it is best to attach it to the frame first.
I then glue the surround to the cone. I have always managed to get all the old surround off the cone. After the old surround is removed, then I tape the face of the driver, lay it flat on some MDF and gently push the cone to the MDF. I the put small blocks of foam between the cone/frame to keep the cone in contact with the MDF. It is easier to work on the removal of the foam from the cone for me anyways.

I would not shim either. I don't like the idea and it seems to me the best method is the tone. Just for the fact if the former has been distorted from some unknown force but still plays fine, shimming may not work where a tone would. I have also used the "By Hand" method and that worked just fine.
Another thing I have found that I use alot is some fine application tips for my glue bottles.

doyall
02-11-2012, 04:28 AM
Appreciate the discussions. Guess I am as ready as I will ever be to tackle it.

Woody Banks
02-12-2012, 09:32 AM
Great thread Tom. I will be sure to try the "Yoda Method" next time. I have always been squimish when it came time to cut away the old dust cap. Without a lazy susan or turntable it is also difficult to get a decent glue line on the replacement cap. Your method solves these issues.

SEAWOLF97
02-12-2012, 09:50 AM
Great thread Tom. I will be sure to try the "Yoda Method" next time. I have always been squimish when it came time to cut away the old dust cap. Without a lazy susan or turntable it is also difficult to get a decent glue line on the replacement cap. Your method solves these issues.

the only problem with the YM is all the special gear that you need ...

hands
quiet room
ability to hear a scrape
patience
;)



one last thing...I did rotate the driver 180 when reinstalling to counter any effects of aging on the spider. (sag..tho didn't see any)

slowpat
03-17-2012, 11:21 PM
the only problem with the YM is all the special gear that you need ...

hands
quiet room
ability to hear a scrape
patience
;)



one last thing...I did rotate the driver 180 when reinstalling to counter any effects of aging on the spider. (sag..tho didn't see any)

Glad it turned out well...I have two pairs of the LE14H-1's to do, and have been procrastinating. Question - after the surround to the basket has dried, how did you apply the glue for the surround-to-cone part? Thanks.

script56
05-08-2012, 06:45 PM
when refoaming the le14, do you remove the black rubber ring in between the cone and basket or put new foam over it? does it go basket, gasket foam or basket foam gasket?

slowpat
05-08-2012, 07:32 PM
when refoaming the le14, do you remove the black rubber ring in between the cone and basket or put new foam over it? does it go basket, gasket foam or basket foam gasket?

When you are scraping off the old foam, you will need to remove the rubber ring so that you can scrape off the foam off of the basket (a very thin edge). After you glue the foam to the back of the cone, you glue the rest to the basket, then put the gasket last. As the previous posts said, you may need to glue the foam to the basket first then the cone, and gasket last.

SEAWOLF97
05-09-2012, 08:27 AM
when refoaming the le14, do you remove the black rubber ring in between the cone and basket or put new foam over it? does it go basket, gasket foam or basket foam gasket?

the black plastic ring nearly covers the ledge on the basket ...if you don't remove it and clean under it..then there is no ledge to glue to.

when I glued the foam surround to the basket, then put a little extra glue ON TOP of the foam lip for the purpose of holding down the black plastic ring. The ring fits tightly enough to hold down the foam while it is drying. Just push down a bit on the top of the ring and it will be flush with the higher edge of the basket.

nelsondog
01-24-2013, 12:19 PM
Hi guys, I'm wondering if that plastic ring absolutley has to be replaced? Mine's a real mess with what seems like baked of glue and it doesn't want to budge...

JuniorJBL
01-24-2013, 12:48 PM
Hi guys, I'm wondering if that plastic ring absolutley has to be replaced? Mine's a real mess with what seems like baked of glue and it doesn't want to budge...

Yes but not replaced, reused. There is only an 1/8" of foam being glued down so the ring adds glue surface to the whole assembly.

nelsondog
01-24-2013, 12:49 PM
Yes but not replaced, reused. There is only an 1/8" of foam being glued down so the ring adds glue surface to the whole assembly.

Thanks for the speedy reply:)

nelsondog
01-26-2013, 08:07 AM
Hi all, I've come up with a method for removing the old adhesive from the black plastic trim ring I thought would be worth sharing with the community.
I used wood glue to apply emery cloth a MDF ring about 8" in diameter left over from another project. Once dry, I used a file to trim off excess cloth that over-hung the edges of the MDF ring. This formed a clean, well fastened curved sanding block. While seated, I held the MDF ring between my knees and began to sand away the old glue with complete control. Using moderate pressure, I rubbed the trim ring back & forth while frequently looking at the result as to not over do and to maintain the original thickness of the trim ring. Within 30 minutes of sanding, I was able to remove all the old adhesive from both edges of both trim rings with ease.
The emery cloth used (medium) was the equivalent to 120 grit sandpaper.
Hope this helps:)

SEAWOLF97
01-26-2013, 09:00 AM
I just softened up the glue with acetone
and nudged it off with a thumbnail and nail file.

bigyank
01-27-2013, 06:52 AM
"removed old foam and cleaned up basket and cone pretty well after removing the black plastic ring."

I inherited a pair of 240ti's in which my le14H-1's are the frame only. My question is since I do not have this black plastic ring, am I wasting my time or does this black plastic ring come as part of a recone kit. I understand the OEM kit is NLA, but I am willing to try an aftermarket kit at this point.

Yank

rdgrimes
01-27-2013, 08:47 AM
"removed old foam and cleaned up basket and cone pretty well after removing the black plastic ring."

I inherited a pair of 240ti's in which my le14H-1's are the frame only. My question is since I do not have this black plastic ring, am I wasting my time or does this black plastic ring come as part of a recone kit. I understand the OEM kit is NLA, but I am willing to try an aftermarket kit at this point.

Yank

How about supplying a photo of the frame in question?

bigyank
02-01-2013, 07:16 AM
Before cleaning them up.

58103

JuniorJBL
02-01-2013, 08:09 AM
I found a kit at a pro dealer and had them recone a -1 for me. It looks like the same ring that was on there originally.

pathfindermwd
02-01-2013, 10:11 AM
Before cleaning them up.


I have doubts about whether the plastic trim actually does anything to strengthen the surround, once the surround is glued down. It does help to get the surround edge evenly pressed down while the glue is drying. Without it, you would need to fashion something to accomplish that. But if the surround is glued down well, it shouldn't come off, all by itself. Consider that 14" in diameter is nearly 44" in circumference. That's alot of bonding surface, even if it is only 1/8" thick. Further, once the glue is dried, the bond should be stronger that the foam itself. Personally, I would feel better with the strip applied over the surround, but I doubt it adds any strength to a well glued edge.

Without having at least one plastic trim around to look at, it's difficult to make a suitable replacement. But if I had to make something I would be looking for a piece of heavy/stiff rubber 1/4" thick or less, cutting two strips 44" long. Finding black plastic would be better but I can't think of what you could get off the top of my head. Aluminum that long is available. Could you cut off two 1/4" strips, carefully bend them around something 14" round, paint them black?
:dead_horse:

All that said, it's really a moot point. You need factory re-cone kits to bring them back to life which would probably come with the trim rings.:D

rdgrimes
02-01-2013, 01:45 PM
But if the surround is glued down well, it shouldn't come off, all by itself.

One would think so, but still we have reports of surrounds coming loose on 14 and 18" drivers with no "gasket" to hold it in place. The plastic trim ring does also adhere to the vertical flange and "clamp" the surround in place.

"Glued down well" is the key I suspect. But I would never feel safe in running a LE14H wide open without that ring. Same with the LE10H, it uses the same stuff. The flange is pretty narrow under that surround, not much there to adhere to.

I wonder if places like Orange Co Speaker might know if the plastic ring is available or part of the cone kit.

macaroonie
02-01-2013, 02:27 PM
Why not try JBL parts to see if they can supply the trim ring on its own. They may have some in a dumpster waiting to get picked up.

Seriously as I recall its a quarter round PVC section about 1/8" on the straight edges. Look on the web for PVC trim sections , you might turn something up.
Worth the effort , it just tidies the job up and makes the speaker look swell.

Failing that you could try stripping the insulation off a suitable cable and then make a little jig to allow you to slit it in half and then half again.

DavidF
02-01-2013, 08:53 PM
"removed old foam and cleaned up basket and cone pretty well after removing the black plastic ring."

I inherited a pair of 240ti's in which my le14H-1's are the frame only. My question is since I do not have this black plastic ring, am I wasting my time or does this black plastic ring come as part of a recone kit. I understand the OEM kit is NLA, but I am willing to try an aftermarket kit at this point.

Yank The two oem kits I had did not include the trim ring.

bigyank
02-02-2013, 09:56 AM
The two oem kits I had did not include the trim ring.

Thanks! :(