Foam surrounds life expectancy?

[T.Rex]

L-300/Summit owners...................approx.life expectancy (in years) before foam surrounds go south?

Thanks!

[rdgrimes]

10 to 30 years, depending on conditions. Exposure to heat, moisture and UV will determine life expectancy.

[Doc Mark]

Hey, T.Rex,

I agree with RdGrimes. I have a pair of Eminence 15" woofers, which I bought as NOS, back in 1983/4. I've carried those things around with me, since that time, hoping to do something with them. Then, I got my JBL dream woofers, 2235H's, and decided to let the Eminence just lay fallow in our Hobbit Hole, which is like our basement, but built up a bit. I just checked them the other day, and the foam is still soft and supple, with no cracking, flacking, or disintegrating, and they have been in that box for over 25 years!! Interesting, eh?! Yet, I've seen the foam on other woofers go South, due to a poor environment, in just a few years. Go figure....

Are you a new L300 owner? Me, too!! I dearly LOVE mine, and can't get over their depth of sound, clarity, and sweet, open presentation!! Have fun with them! Take care, and God Bless!

Every Good Wish,
Doc

[T.Rex]

Interesting story Doc.......Yes I do have a very nice pair of 1977 summits. I am the second owner and they sound and look like new. Just a little curious about the surronds is all. Mine look like new as we speak. I wonder if NOT using the woofer is actually why they survived so long. Stressing them may accelerate the process?.....Someone may want to chime in on thier opinion.

Thanks

[Doc Mark]

Evening, T.Rex,

Your L300's sound great, pun intended! Since you know their date of manufacture, or close to it, you might want to consider registering the serial numbers of your cabinets, and all separate components, here at LH. Your doing so will help keep a permanent record of the various serial number, with no names attached, for owner protection, and that will help other L300 owners date their own speakers. I'm trying to date mine, even as we speak. So, please consider registering the serial numbers. It's safe and a good thing to do. Thanks, and God Bless!

Every Good Wish,
Doc

P.S. I have the L300's, and also a 4333 project in the works, for which I have another pair of 2235H woofers. Those, I bought from a friend, who bought them new, back in the '90's. He kept them in a very damp place, which was his downstairs area/music room/master bedroom. Because it was damp down there, his foam surrounds didn't even last 5 years! When I bought them from him, I had to have the surrounds replaced, which I did immediately after taking delivery of them. Food for thought....

[toddalin]

Interesting story Doc.......Yes I do have a very nice pair of 1977 summits. I am the second owner and they sound and look like new. Just a little curious about the surronds is all. Mine look like new as we speak. I wonder if NOT using the woofer is actually why they survived so long. Stressing them may accelerate the process?.....Someone may want to chime in on thier opinion.

Thanks

I will.

On both my L112s and RSL 3300 (L112 wannabes), the foams looked and felt fine.

Then a friend who used to work at RSL asked to hear them (they were about 18 years old). When "cranked" they blew the foams right out of the speakers even though they still looked fine.

The L112s did the same except that the foams merely split rather than shot off pieces.

On my CV surrounds (about 15 years old), the one speaker that was jostled when it almost fell from the ceiling split its foam into pieces. On the other three (when I took them all down), the foams still seemed fine, but all are the same age, so they must also be deteriorated. All the CV components were replaced with JBL (W10GTi/2425Js) with rubber edges that should never need replacement.

What I'm getting at is that the foams can look (and feel) fine even after 15-20 years, but that's no gaurentee that they won't split the first time they get a nice "hit of bass."

[JBL 4645]

Why can they just be replaced with rubber edge surround afterwards I mean talk about a load of hassle in stripping it all down and replacing it with the same foam edge surround, nothing but hassle.

10 to 30 years, depending on conditions. Exposure to heat, moisture and UV will determine life expectancy.

And what about living near to the ocean slat-air so that would mean living anywhere near to shoreline is bad, so JBL owners with foam edge surrounds, move to the centre of the USA to prolong the usage of the edge foam surrounds.

First I noticed about 13 years since I purchased my first set of three JBL control 5 (1990) (2003) the sound one day had a weirdness to it. After removing the grill and checking over with touch I noticed a small slit that was length ways around the edge foam surround by about 15mm or so. So all the bass mid low end was venting out the hole.

[3dbdown]

Foam surrounds in LA......5 to 6 years

[SEAWOLF97]

Why can they just be replaced with rubber edge surround afterwards I mean talk about a load of hassle in stripping it all down and replacing it with the same foam edge surround, nothing but hassle..

A huge number of people on the forum do this regularly ...it really is not that bad and actually somewhat relaxing (long as you aren't under a production schedule)