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View Full Version : Quick woofer seal questions (LE-10)



Ralph856
12-21-2009, 10:05 AM
Hi

What's the best glue to use? (I have at hand a tube of the 'Bostik, all purpose, dries in minutes' variety)

Should the seal be showing at all after the woofer is in place, as in the photo?

Thanks



http://i204.photobucket.com/albums/bb184/DavidS_025/wooferseal1.jpg

Robh3606
12-21-2009, 10:27 AM
There is a recessed ring in the woofer frame where the round gasket goes on the driver. You should still be able to get them. Try JBL Pro. Look through the Tech Sheets for the Part Number


What's the best glue to use?

None!! Don't use glue. Use a non-hardening gasket material. You can get it at Parts Express as one possible source.

Rob:)

Ralph856
12-21-2009, 10:51 AM
Dammit, that shows the importance of asking when you're not sure. Didn't even notice the recessed ring :o:. Parts Express is in Canada so will need to find non-hardening material closer to home. Any suggestions from UK'ers appreciated.

Thanks, Rob

One more thing: noticed that one woofer has a tiny wire (see below) while the other doesn't. Is this a problem?

http://i204.photobucket.com/albums/bb184/DavidS_025/smallwire.jpg

Eaulive
12-21-2009, 12:06 PM
Dammit, that shows the importance of asking when you're not sure. Didn't even notice the recessed ring :o:. Parts Express is in Canada so will need to find non-hardening material closer to home. Any suggestions from UK'ers appreciated.

Thanks, Rob

One more thing: noticed that one woofer has a tiny wire (see below) while the other doesn't. Is this a problem?

http://i204.photobucket.com/albums/bb184/DavidS_025/smallwire.jpg

If you're talking about what's in the center of the picture, it's not a wire, it's just a thread of glue that dried there.

ratitifb
12-21-2009, 02:10 PM
If you're talking about what's in the center of the picture, it's not a wire, it's just a thread of glue that dried there.the excess of glue on back of the cone is a more important issue :(
Who has made the refoam job :o: ?

ROSSO
12-21-2009, 02:39 PM
Hi

What's the best glue to use? (I have at hand a tube of the 'Bostik, all purpose, dries in minutes' variety)

Should the seal be showing at all after the woofer is in place, as in the photo?

Thanks
You should never need any glue or gasket to mount the older LE series to the baffle (LE120H an exception, and I have never seen a LE14H-x) I take it that this driver is not original to the cabinet you are installing it in, correct? All of the o-ring LE series woofers are very particular about the cutout size. There was originally a PVC o-ring around the back that sealed the frame to the front baffle. If the hole is too large or irregularly shaped the o-ring won't seal, too small, and the frame won't seat.

Ralph856
12-21-2009, 02:57 PM
the excess of glue on back of the cone is a more important issue :(
Who has made the refoam job :o: ?

A 'respected' company called Wembley Loudspeaker. It's the same on both drivers. Is it really bad?

http://i204.photobucket.com/albums/bb184/DavidS_025/glue.jpg


One driver also buzzes when there is really strong bass. I'm hoping it's not to do with the voice coil beginning to separate from the cone. Is there any way I can take a close up photo to prove one way or the other?

Ralph856
12-21-2009, 03:07 PM
You should never need any glue or gasket to mount the older LE series to the baffle (LE120H an exception, and I have never seen a LE14H-x) I take it that this driver is not original to the cabinet you are installing it in, correct? All of the o-ring LE series woofers are very particular about the cutout size. There was originally a PVC o-ring around the back that sealed the frame to the front baffle. If the hole is too large or irregularly shaped the o-ring won't seal, too small, and the frame won't seat.

To the best of my knowledge, the drivers are originals and the cabinets were in excellent shape when I bought the L96's last summer.

So, you think I shouldn't use any kind of gasket, even non hardening material?

Robh3606
12-21-2009, 06:25 PM
So, you think I shouldn't use any kind of gasket,

The original white "O" ring is the gasket. If it's in good shape and the cabinet cut-outs are not chipped or have missing edges you should be OK.

Rob:)

ROSSO
12-21-2009, 07:27 PM
Should the seal be showing at all after the woofer is in place, as in the photo?
If the white is the o-ring extruding out from under the flat side frame, looks like it just needs to be reseated in it's groove. Still shouldn't need any type of sealant.


...One driver also buzzes when there is really strong bass. I'm hoping it's not to do with the voice coil beginning to separate from the cone. Is there any way I can take a close up photo to prove one way or the other?You an use an adhesive remover on the glue that fixes the dust cap to the cone, then gently separate the cap from the cone. The cone-voice coil joint is then visible. It can be reglued if it's notcompletely separated. You should shim the voice coil to do so. Paper shims are likely the right thickeness. I just did exactly this to a buzzing LE-14A I was given for free. Works great now.

Ralph856
12-22-2009, 03:44 AM
You an use an adhesive remover on the glue that fixes the dust cap to the cone, then gently separate the cap from the cone. The cone-voice coil joint is then visible. It can be reglued if it's notcompletely separated. You should shim the voice coil to do so. Paper shims are likely the right thickeness. I just did exactly this to a buzzing LE-14A I was given for free. Works great now.

Lol, that may prove a bit tricky for me to attempt to do ;). Looks like I'll have to take it back to the shop who did the refoam.

Out of interest, is all that glue on the back of the cone bad work that I have the right to ask to be removed? If they were to remove the glue (free of charge) I could also ask them to check out the cause of the buzzing at the same time. Might make doing that a bit cheaper.:hmm:

Ralph856
12-22-2009, 03:54 AM
The original white "O" ring is the gasket. If it's in good shape and the cabinet cut-outs are not chipped or have missing edges you should be OK.

Rob:)

The one white O ring that was glued is still usable but not perfect anymore. The other O ring is fine because I never touched it ;) :p

Is it possible to buy replacement O rings? Edit: you answered that previously.

http://i204.photobucket.com/albums/bb184/DavidS_025/Oring.jpg

As far as the one woofer cut out that was glued is concerned, I applied a tiny drop of superglue at various points rather than around the whole circumference, so it's not too bad. Unfortunately, removing the O ring took off a little paint.

http://i204.photobucket.com/albums/bb184/DavidS_025/woofercutout.jpg

grumpy
12-22-2009, 07:30 AM
I've soaked those white o-rings in hot water and had them
return closer to the original shape...

Ralph856
12-22-2009, 08:07 AM
I've soaked those white o-rings in hot water and had them
return closer to the original shape...

Thanks



the excess of glue on back of the cone is a more important issue :(
Who has made the refoam job :o: ?

Could you please elaborate on this comment from yesterday? Is the excess glue serious and can it be rectified by the people who did the refoam?

badman
12-22-2009, 09:38 AM
Thanks




Could you please elaborate on this comment from yesterday? Is the excess glue serious and can it be rectified by the people who did the refoam?

It's ugly but not a serious issue.

Ralph856
12-22-2009, 09:41 AM
So not enough of a reason to take up with the shop?

ratitifb
12-22-2009, 11:13 AM
Quote:
Originally Posted by Ralph856 http://audioheritage.org/vbulletin/images/buttons/viewpost.gif (http://audioheritage.org/vbulletin/showthread.php?p=273429#post273429)
Thanks




Could you please elaborate on this comment from yesterday? Is the excess glue serious and can it be rectified by the people who did the refoam?



It's ugly but not a serious issue.i agree with that but this refoam job isn't correct (state of the art ;) ). Excess of glue is equivalent of added mass on the cone and the stiffness/damping characteristics of the cone are locally modified in the glue area ...

Ralph856
12-22-2009, 12:15 PM
Would that, in your estimation, be sufficient reason to ask the shop to clean the cones up at their expense?

LRBacon
12-22-2009, 03:24 PM
A 'respected' company called Wembley Loudspeaker. It's the same on both drivers. Is it really bad?

http://i204.photobucket.com/albums/bb184/DavidS_025/glue.jpg


One driver also buzzes when there is really strong bass. I'm hoping it's not to do with the voice coil beginning to separate from the cone. Is there any way I can take a close up photo to prove one way or the other?


I would check to make sure the surround is completely glued to the cone all the way around it. At higher volume levels it will flap in the breeze so to speak and cause a buzzing type sound. I doubt very much that the cone is separating from the voice coil.

Larry

grumpy
12-22-2009, 03:46 PM
might also want to verify that the "tinsel" leads (between terminals and cone)
are routed such that they don't hit/touch the cone when large inward excursions
take place...

Ralph856
12-22-2009, 03:59 PM
thanks and thanks. For some reason it's starting to distort MUCH more than before and even at quite low volume with minimal bass! The only thing that has changed (since it wasnt distorting so much) is that I turned the driver 180 degrees today. Hmmm :hmm:


I'll take the driver out and have another check.

grumpy
12-23-2009, 08:12 AM
sounds like a rubbing voice coil...

might start looking for a used replacement or recone-type repair if you
wish to keep the speakers, or sell them and cut your losses.

Eaulive
12-23-2009, 08:51 AM
sounds like a rubbing voice coil...

might start looking for a used replacement or recone-type repair if you
wish to keep the speakers, or sell them and cut your losses.

Yes, it does sound like that.
To make sure gently push the cone by pressing on the outside of the cone, close to the surround. Theorically it should not rub, or maybe very slightly when pushed deep enough.
Do this at every 90 degrees around, if the cone rubs, it should at least rub equally from all angles. If it does not rub from an angle but rubs ALOT from the opposite angle (180 degrees) with the same pressure, it's definitely off center.

Of course if it rubs when pushed equally from around the dust cap, it's a no-brainer :D

Ralph856
12-23-2009, 12:34 PM
Just tried it. It seems to move freely about 4/5 of the cone but for 1/5 the cone suddenly stops moving, as if there is something solid behind it.

Guess what? It's does the same thing in exactly the same place in the other cone, too.

Eaulive
12-23-2009, 07:32 PM
Just tried it. It seems to move freely about 4/5 of the cone but for 1/5 the cone suddenly stops moving, as if there is something solid behind it.

Guess what? It's does the same thing in exactly the same place in the other cone, too.

You're hitting the back plate, it's normal. Actually it's not 4/5, it's 5/5 since it will never go further. Don't force it too much!
Usually you don't have to push it down so far to feel if it's rubbing.

On second thought, if it distorts more after rotating the woofer 180 degrees, it could also be the baffle surface that is not flat and/or a deformed basket that binds the coil off center.