Glue Question

[DONALD G]

Hello,

After 25+ years of hard use, I have developed a problem
with one of my L100 speakers. When turned up I hear
a "snapping" noise out of the 123a. After closer inspection
I found that the cone is starting to separate from the spider.
Doing a search of this forem, the best advice was to use a
carpentry type cyanoacrylate glue which I have not been able
to find ( not at home depot,lowes or the local hardware
stores ). Does anybody know of a specific glue that they
have used, and where to buy it ? Has anyone used the speaker
repair glue that parts supply sells ( 340-076). Any help
would be greatly appreciated.

Don

[Robh3606]

I had a similar problem where the spider was seperating from the coil/cone base. Its hard to get at to make sure it gets glued in the right position. What I did was remove the magnet assembly from the frame, reglue with the surround glue. You can get it from Parts Express. And just carefully put the magnet back on the frame. There are two alignment keys/pins in the frame so if you are careful it can really not be a big deal. Just make sure you mark the frame with an index mark so it goes back in the same oreintation. They are offset so you really can't get it back together wrong just be careful you don't damage the voice coil. If you are not comfortable don't do it. You can always bring it to a JBL service center if you have one close by to see if they can fix it. Attached is a photo of a spare 123A frame with the magnet detached.


Rob

[subwoof]

2 part epoxy is the preferred glue for that junction - the glue that you mentioned ( the hard to spell one ) is the basic crazy glue......

you will *want* the set-up time that epoxy affords....



sub

[boputnam]

Originally posted by DONALD G
After 25+ years of hard use...

I agree with subwoof on the need for lengthy setup time - you've got to make sure things are all properly centered.

But, I question the entire exercise. If one woofer has this damage, assuming you've not been monaural, the other 123A has seen the same signal pattern.

I suggest a recone on both LF's if you're fond of the original sound those L100's produced...

[DONALD G]

boputnam you are right - I purchased 2 pair of L100s in
the mid seventies, and three out of the four base speakers
are starting to show a split between the spider and cone,
but only 1 sounds bad. The snapping noise only occurs at
high volume and when the bass is strong - bass drum.

The split is only about 20 % of the circumference of the
cone / spider joint, and is hard to see unless you push
the cone out and look carefully. Because of this I don't
think i will have a problem with keeping the cone centered
during the repair. Pulling the magnet was easy, which gives
me a clean shot at the joint. Thanks to Robh3606 - my original
plan was to try to do the glue job without taking the speaker
apart. That would have been a mistake. I ordered a tube of
cyanoacrylate gel glue from parts express - the saleman confirmed
that this would be the best glue for the job. A small bead of glue
around the joint should do the trick.

I surely can't be disappointed with my purchase of these speakers
The ink stamp on the inside of the voice coil - JAN 15 1975

[jbl]

I bought my pair of L-100 in November 1975. They were one of if not the best sounding speakers in their size class at the time, regardless of price. They still sound great after 28 years.

[boputnam]

This is really a dangerous Thread for me...

[Ian Mackenzie]

Resist the Temptation Bo,

It also epends on how often if ever you have your ears waxed Giskard.

Ian

ps wheres Tooths...

[boputnam]

Originally posted by Giskard
I'd advise you to dump those 4345 battleship anchors you have and do the same.

Actually, I fought the urge to reveal this to Ian - he was so anxious to build those lame refridgerators - but the 4345's are fraud. I discovered this collecting measurements for Ian.

There's really four L100's stacked in each cabinet...

[Ian Mackenzie]

Yeah,

I got my pair the Altec Duplex 604 ((L100's) emulators flanking the main coolers.

So why have you dismantled those much loved 4430's? What surround sound amp are you using?

Ian

[boputnam]

Giskard...? Dammit - we almost had him!!

That was his desperate call for ... He was just about to admit that he is "thoots", and in truth simply fawns over his 12-dozen pair of L100's...

[jbl]

Bo and Ian. I knew you could'nt resist responding in some way about an L-100 question. Just wanted to see how easy it was to push your buttons.

[boputnam]

Originally posted by jbl
Just wanted to see how easy it was to push your buttons.

Yea, well you shook Giskard from the bushes, too, but the rascal vaporized hisself...

[DONALD G]

Hey if it were not for all of us chumps that bought
the L100, JBL would have gone out of business
and you guys would all be sitting around trying
to fiqure out how high you could stack your advents
and wondering if your sansui 9090 could handle .005 ohm.

All of us L100 owners should start our own forum
and not let you guys play. NA NA NA

[Ian Mackenzie]

This thread should be titled the chain reaction.

Sounds like Giskard building a 4344 out of the 4430 scap parts?
Why else would he dismantle his 4430's?


Ian