Need L-212 Help

[snerty]

Newbie here with lots of questions.
Trying to save some L-212's (sadly missing sub):
What type of paint was used on the speaker box faces? (rubberized?)
Is it safe to coat peeling 066's with aluminized paint?
Was the foam on the 112 A's originally grey?
Who sells the best after market foam replacements?
What is best for 112 A's: refoam using test tone (9-V battery) or cutting dust cap and using shims?
Is it worth the loss of originality to change L5-9 inverted dust caps to aluminum?

I'm sure you've answered these questions multiple times and appreciate your patience & help.

[grumpy]

Is it safe to coat ... 066's with aluminized paint?

Apparently JBL thought so.

[speakerdave]

. . . . Was the foam on the 112 A's originally grey? . . . . .

If you are asking was it originally lansaloy cream--no, it was not.

. . . . Who sells the best after market foam replacements?
What is best for 112 A's: refoam using test tone (9-V battery) or cutting dust cap and using shims? . . . .

We get them from Rick Cobb, and he will include a CD with a 30 Hz test tone. It is the method I've used, and it seems to work for me. There's an illustrated step-by-step somewhere in these forums.

. . . . Is it worth the loss of originality to change L5-9 inverted dust caps to aluminum? . . . .

I don't know.

David

[brutal]

... Rick Cobb, AKA looneytune2001 on ebay...

[snerty]

thanks for the help folks. Just want to clarify the 066 question. Somebody recommended testors aluminized model paint to take the place of the missing vapor deposited coating. The tweeters work great as-is, so I do not want to screw them up if the paint trick doesn't protect or prolong their life span. Just being paranoid

[speakerdave]

thanks for the help folks. Just want to clarify the 066 question. . . . Somebody recommended testors aluminized model paint to take the place of the missing vapor deposited coating. The tweeters work great as-is, so I do not want to screw them up if the paint trick doesn't protect or prolong their life span. Just being paranoid . . . .

There is a tale in the oral history that when the vapor deposition machine broke down the domes were spray-painted with aluminum (suspension?) paint, and the 066's sold toward the end of the run were made that way. That's what grumpy was referring to. Whether that is to be taken as gospel--who knows?

Let us know how it turns out.

David

[grumpy]

I have no 066 tweeters, however:

I have multiple 044's and a NIB JBL D8R044 kit. Some are vapor deposited Al, some
are painted (including the stock kit). The difference in appearance, side-by-side is
obvious. It's also quite easy to tell with an ohmmeter, as the paint is not particularly
conductive (safer to check this with the unit disassembled). The difference in sound?
I can't tell, and haven't yet bothered to measure. If I do, I'll certainly post. -grumpy

Opinion:
prolong life span? It's phenolic-impregnated linen under the Al (or paint)...
short of a gerfingerpoken incident... the dome should not be a problem. You could smoke
the voice coil or worry about the likely deteriorated foam plug under the dome, but
these units have lived their life span. Enjoy them while you can.

[57BELAIRE]

Newbie here with lots of questions.
Trying to save some L-212's (sadly missing sub):
What type of paint was used on the speaker box faces? (rubberized?)
Is it safe to coat peeling 066's with aluminized paint?
Was the foam on the 112 A's originally grey?
Who sells the best after market foam replacements?
What is best for 112 A's: refoam using test tone (9-V battery) or cutting dust cap and using shims?
Is it worth the loss of originality to change L5-9 inverted dust caps to aluminum?

I'm sure you've answered these questions multiple times and appreciate your patience & help.

Personally, I would refoam the 112A's and keep the cones as original
as possible. I don't think cone kits are available anymore.

As for a test tone, a 9 volt wouldn't be my first choice. Any program material supplied at low volume should suffice...you don't want the cone
jumping all over the place when refoaming.

What's the purpose of changing the dust caps? "If it ain't broke...don't fix it"

[snerty]

What a great site. you guys are a fount of valuable info.

[MJC]

Personally, I would refoam the 112A's and keep the cones as original
as possible. I don't think cone kits are available anymore.

I've had 2 pairs of 112A re-worked by Orange County Speaker, one pair they did a full recone, replacing the rib cones with smooth cones.
The other pair was done after the kits were no longer available, so they just replaced the surrounds.
Listening to them, I can't hear any difference.