Refoaming woofers

[bestbier]

Check this:

http://www.goodhifi.com/Movies/Refoa...%20kleiner.wmv

[rcavictim]

I don't think anyone would argue that when the woofer factory put foam surrounds on woofers that today are rotted away, THAT THEY MADE A MISTAKE.

My question is forearmed with this knowledge, WHY would one want to spend hard earned money to duplicate a mistake?

Now, if you are trying to upgrade a rotten foam surround driver with a new surround that is not foam, I'm all for that. I have not seen butyl rubber or corrugated and treated cloth replacement surrounds available however. Anyone here know of any?

[HK26147]

There are suppliers of surround repair kits in rubber and foam and specialized cloth pleated. ( Parts Express, MCM are 2 )
My experience is that the the 1st generation of speakers that utilized foam surrounds (70's?) have long since rotted. The successive generations of foam surrounds have gotten more durable in their composition or are coated.
Speaker Builder magazine had articles on anti-rot treating the surrounds and repair in the 80's.
The numerous speakers I have repaired that had rotted surrounds, have ( so far ) not rotted out again, after 15+ years.
A big factor in the surround longevity is the operating environment:
Cool stable conditions are better than the extreme temp swings in an auto, and exposure to sunlight that occurs on deck speakers.

[nickmckinney]

Foam is a much better damped material than rubber and it also supports the cone better. I started treating it with a damper coating and haven't heard of one of my foams dying yet after 10 years.

[CLS]

I've used silicon oil on the foam surrounds and got good result, too. EV's bought in '95 are still in very good condition today, almost look and touch like new

[LAJ]

is that it is a very large molecule and those, by their very nature, are unstable and decompose relatively quickly. Most likely the new foam surrounds are improved in composition but they, too, will eventually decompose.