We've been surrounded! What are our chances?

[Chef Henry]

I have a shot at 5 sets of 4320 components. These were removed from their cabinets, which except for 1 pair, were trashed beyond redemption. (The surviving pair has been painstakingly rebuilt and veneered in walnut, needing only a light sanding, stain, finish, and grills to be complete.)

Over a decade ago, the woofers and tweeters, which were all blown, were fully restored by Eric Wayne of Gabrial Sound, an authorized JBL service provider in Pompton Lakes, New Jersey. Eric replaced the tweeter diaphrams with the correct factory part, and retrofitted the woofers with new cones, coils and surrounds. Immediately after their restoration, they were put back into their cardboard shippers, and stored in an unheated attic.

The seller, himself a former JBL contractor, claims that the foam surrounds are as good as the day they were installed, and have not deteriorated because they have not been used or exposed to light. Naturally, I would like this to be true, and will know for sure when I inspect them prior to sale. But I am curious to know how the members of this esteemed Forum estimate the chances that the surrounds remain servicable.

[grumpy]

not deteriorated because they have not been used or exposed to light.

... insufficent information. You'll have to inspect.

Fellow where I work did a multi-year experiment where two identical foam pieces were
put into a cool/dark closet, one in a zip-lock bag (closed), one in a zip-lock bag (open).
At the end of the experiment, the open-bag piece crumbled to dust when touched...
closed bag piece was fine/pliable/"as-new". The materials were not the same as speaker
surround "foam", but I'll go out on a limb and say I would expect similar results.

-grumpy

[toddalin]

Are you going to see the speakers?

If so, it's a simple matter to have the owner lightly rub the surrounds to see if any flaking occurs. If no flaking is observed, they are probably good to go. If they do flake..., well.

If the owner will not touch the surrounds to demonstrate this, he may be the flake, and I would either pass on the speakers, or be ready to pay for new surrounds to install or be installed.

[Audiobeer]

Aren't they paper surrounds?

[Zilch]

http://www.lansingheritage.org/html/.../1972-4320.htm

Originally, "An indeterminate variant of mucus...."

[subwoof]

It's the exposure to oxygen that does them in. Smog, UV, moisture and heat add to the demise but if they were sealed in bags you are probably good to go.

No different than storing raw meat in the fridge.

JBL sold a LOT of 2245H ( OEM ) speakers for cheap at the original tent sale in 1997. They were the original driver specified for the concert series dual 18 flying subwoofer. ALL of them were foam rotted when the SEALED factory box were opened but of course, were under warrantee so they were rebuilt.

A steal..

I have opened NOS recone kits and had similar problems so when I buy them I also order new foams from rick cobb and replace them *before* reconing.

sub