Foam surrounds

[mzisserson]

Does anyone have any idea how to improve their life expectancy? Just a thought, but if one could, they may make some serious $$$...

[daver]

I don't know if there's a chemical treatment for the foam type surrounds, that may be something you are asking about.

My understanding is that the formulation for foam surrounds used today has better rot resistance than the stuff from the '70's or 80's, for instance.

I would suspect that keeping the drivers out of direct exposure to sunlight (UV especially) may help them last longer. In addition to the drivers and surrounds, a friend was disappointed to find the finish on his walnut cabinets had faded after being by the southerly-exposed windows in his front room for a few years.

Some places stock butyl rubber surround replacements, as well as foam.

[critofur]

In addition to using longer lasting foams most manufacturers use a UV resistant coating. That is, on those few models still sold w/foam surrounds - most seem to have moved away from using foam for surrounds because of their perceived poor quality among consumers.

[dlr]

In addition to using longer lasting foams most manufacturers use a UV resistant coating. That is, on those few models still sold w/foam surrounds - most seem to have moved away from using foam for surrounds because of their perceived poor quality among consumers.

That is unfortunate. In some situations foam is better than rubber. The key is the impedance matching between diaphragm and surround. Foam is apparently better for materials such as Kevlar and fiberglass, possibly due to the weave pattern used. The SS 21W/8554 is a prime example. I've got a pair I bought used years ago and they still look fine.

The new4" midrange from SB acoustics uses foam. Note that they make no comments on this in their copy, probably to prevent prejudice against it. The measurements indicate that it works pretty well.

The coating is for more than UV, I think it's also meant to seal out oxygen.

dlr

[DDF]

Try and keep the humidity in your house down. Foam rot is accelerated by humidity which allows the molds which eat the foam to proliferate.

I personally learned this the hard way and lost a few woofers. I even had Sonex foam eaten by mold to a state of uselessness.

Dave

[johnastockman]

The newer material for foam surrounds is coated, so the deterioration isn't like it used to be. My old Speakerlab S2's had a 10" woofer with foam, they lasted from 1977 'til 1995 before they disintegrated to dust. I don't know of any coating to keep it from happening w/o changing the properties. I wouldn't worry about any newer drivers with the foam....but I could not tell you WHEN manufacturers started using it and the coatings.

John A.

[PassingInterest]

Bob Carver recommended applying Mink Oil periodically to the foam surrounds on his SunFire Subs.

I had to look it up, because I didn't even know what it was.
It is a leather care product, used to keep leather soft, supple and plyable to avoid leather drying out and cracking.
From the little investigation I've done, Mink Oil appears to be the prime ingrediant in most leather care products.

I now use it on the foam surrounds of my drivers, but I only started about a year or so ago. I'll update you on how well this works in about 20 years.

Again, this is to prevent damage. Once they're cracked, the damage is already done.

[mzisserson]

Bob Carver recommended applying Mink Oil periodically to the foam surrounds on his SunFire Subs.

I had to look it up, because I didn't even know what it was.
It is a leather care product, used to keep leather soft, supple and plyable to avoid leather drying out and cracking.
From the little investigation I've done, Mink Oil appears to be the prime ingrediant in most leather care products.

I now use it on the foam surrounds of my drivers, but I only started about a year or so ago. I'll update you on how well this works in about 20 years.

Again, this is to prevent damage. Once they're cracked, the damage is already done.

That's the info I am looking for. A buddy told me to use Vaseline, but I am fairly sure a petrol product will EAT the foam.

[Æ]

Try and keep the humidity in your house down. Foam rot is accelerated by humidity which allows the molds which eat the foam to proliferate.

I personally learned this the hard way and lost a few woofers. I even had Sonex foam eaten by mold to a state of uselessness.

Dave

Same thing happens with the light baffle foam/weather strip found in better film cameras. It begins to rot after a number of years and can ruin your camera.