Rsound Foam Failure after 11 years - Large Advent

[Pete B]

Anyone know if Rsound foam supplier is still in business?

I refoamed a pair of 5002 Jensen Advents with the round magnet Jensen woofers (not that it matters)
and loaned them to a friend who had them in his modern barn/art studio about 11 years ago. I got
them back recently, looked them over quickly and hooked them up for a listen. They seemed to have
no bass. Went to hook them up to a measurement system and gave the woofer a push test for air
leaks and what do you know? The foam was ripped half way around the edge of the cone. It feels
soft like when they fail due to age. Inspected the other one and it is failing in the same way.

I was hoping to get 15 to 20 years from these and had heard that better materials were used in
newer foam. I used this foam for all types of LA woofers, OLA, NLA, Jensen and can check a few
others.

I also have a pair of NLA woofers that were "professionally" refoamed maybe 15 years ago, they are
also failing.

Edit: Our OLA s also failed, these were done about 12 years ago, in fact all the LA variants that
I refoamed over 10 years ago are failing.

I actually found the receipt for buying the Rsound foam and there was no date on it but my
credit card expiration was 2008.

Anyone else with age reports? I really don't want to do all these woofers over again.

 

[Big Tuna]

Yep. I refoamed a pair of Marantz M10’s barely 10 years ago, and I bought surrounds from now defunct OCS(Orange County speaker). I didn’t think nothing of it at the time, but wondered why the surrounds were pretty thin and compliance of them was pretty weak. They were half as thick as originals, but correct dimensions. It was pretty much my only option at the time, as the thicker ones they sold were not compatible dimensionally. Come to find out they had their stock from a cheap Chinese supplier which made foams too thin and with no UV protection. Now they look as if they’ve never been touched for 40 years. I’m actually glad that place folded, but the technician who worked for them is still operating and probably still using that Chinese crap for unsuspecting customers.

 

[Guido57]

I wonder if there are any AK members out there with access to an analytical lab who might care to investigate what the basic material is used in these foams.

 

[Guido57]

Note: One glossary from an online component dealer declares polyester foam is used for speaker surrounds and one surround supplier has answered that their foams were made from polyether, both of which are in the polyurethane family. This is far from a final answer as there may be many factors that can affect the quality and longevity of the foam. As the original surrounds from my 1978 NLA's showed no visible degradation for at least thirty years I am very curious as to why people are having issues with ten year old surrounds. And for the record, Pete is pretty picky about his surrounds.

 

[Pete B]

I was thinking the same thing, that the original foams lasted at least 20 years. It is possible that
very cheap look alike foam from "who knows what" kind of material is being sold as top quality.

 

[lukiedog]

Yes, I experienced early failure on my refoamed 4002 woofers I converted to an econowave some 7 years ago. I think I got mine from looneytunes2001. They were the proper thin wall foam with flat inner ring mounted out front on the pincushion frame. I agree, they should have lasted longer. I never got these speakers to sound like it was worth the effort to redo the crossover and install the Selenium D220Ti with JBL waveguides. A bust of a project, really. I pursued the project on the strength of how well the Minimus 77 zilch mod worked on that speaker. These are a dud, though, I will have to eventually part out so someone can make use of the parts.

 

[Guido57]

A little further investigating has two more sellers stating their surrounds are polyether, anyone with a clue as to what was used in the originals? While both polyester and polyether fall under the category of polyurethanes, manufacturers of these materials indicate that polyether is more resistant to UV and moisture and should have better structural strength. A further question is where are the vendors we use getting the surrounds from.
(Polyester should be more resistant to abrasion and tearing, which is why your leisure suit looks as good now as it did in 1976. (I just couldn't resist that one.))

 

[sKiZo]

What makes life interesting is that suppliers seem to be under the impression that the only requirement is that their surrounds fit your speakers physically, audio characteristics be damned ...

My last purchase from OCS was new surrounds for the big woofs on my McIntosh XR16's. Shortly after refoaming them, one went open, so I packed both down to The Circuit Shop right down the road from me. First thing the counter guy said was "nice re-foam ... too bad they're the wrong surrounds!" I'd thought some perceptible loss of bass was due to stiff speakers waiting to break in, but no ... the profile was all wrong and restricting cone travel. (mutter mumble)

Short version - I had them redone from scratch with the RIGHT parts and difference was well worth the expense.

 

[quiet]

This is what Simply Speakers in Tampa FL used on my OLA in 2002. All is well at this time. The tweeter has not been serviced, it's fine too.

 

[Chris Brown]

I think part of the issue is that foam ages, even if it's still on the shelf at the store or warehouse. Some of these places that sell replacement foam might have got those foams 10+ years ago, but I'm sure they are in no hurry to throw away and replace unsold inventory, just to make sure they are selling foam that is as new as possible. I had my JBL L150 speakers refoamed nearly 2 decades ago, my L100T speakers refoamed about a decade ago, and my 4412 speakers refoamed maybe 7 years ago. All are still going strong since then.

 

[Pete B]

I think part of the issue is that foam ages, even if it's still on the shelf at the store or warehouse. Some of these places that sell replacement foam might have got those foams 10+ years ago, but I'm sure they are in no hurry to throw away and replace unsold inventory, just to make sure they are selling foam that is as new as possible. I had my JBL L150 speakers refoamed nearly 2 decades ago, my L100T speakers refoamed about a decade ago, and my 4412 speakers refoamed maybe 7 years ago. All are still going strong since then.

Yes, makes sense.
Several sellers are claiming that these are a newer and better formulation that lasts longer, so
much for that. If they tear after 11 years then the reality is that they DO NOT last longer.

 

[Pete B]

This is what Simply Speakers in Tampa FL used on my OLA in 2002. All is well at this time. The tweeter has not been serviced, it's fine too.
View attachment 1612597 View attachment 1612598 View attachment 1612599 View attachment 1612600

That looks exactly like the foam that I used, but who knows?
Edit: I took a closer look at that and that foam looks dimensionally wrong, and that is probably
another type I've seen that is shiny on at least one side as if there is some sort of coating.

 

[Guido57]

From Loudspeaker Components, a US company that makes various components that go into speakers, responding to an email:
"Polyester surrounds were used exclusively until about 1985 in our company then polyether was introduced. Both are still used . Polyether last longer in terms of rot but tears easier than polyester..

Any coating may help protect against the problem polyester has which is moisture. Polyester is prone to degradation per what is called hydrolitic instability."

Which pretty much echoes what the foam manufacturer said, with the addition that this company's older surrounds were all polyester. Considering additives and manufacturing techniques are most likely improved since the 70' and 80's I would have to say considering the time sitting on a vendors shelf waiting for an order was an excellent point to bring up. There was one vendor who said they sold only fresh surrounds, but I'm not sure I can name them here without getting my post deleted.

Never heard of Rsounds, but I didn't get into replacing surrounds until my NLA's failed five or six years ago. Now I'm deeper into this shit than ever.

 

[Bill Murray]

I wonder if there are any AK members out there with access to an analytical lab who might care to investigate what the basic material is used in these foams.

I am so lucky I bought all my speakers before the new "improvement" of foam surrounds came into being. I would not buy any speakers with foam surrounds, even if they are in good shape.

 

[Blue Shadow]

Something that might cause some differences is the Montréal Protocol, 1987, the introduction of changes in the foam blowing agents used as previously they were frequently CFCs and HCFC where are not being used in first world countries anymore.

 

[FluxT]

I wonder if it’s at all possible to replace the foams with something more durable, like rubber or cloth, without changing the vital aspects of the woofer.

 

[quiet]

I doubt it.

 

[Pete B]

From Loudspeaker Components, a US company that makes various components that go into speakers, responding to an email:
"Polyester surrounds were used exclusively until about 1985 in our company then polyether was introduced. Both are still used . Polyether last longer in terms of rot but tears easier than polyester..

I've refoamed about 4 pairs of LA woofers since I started this thread and have been thinking a lot
about this. Great info above where they state that it tears easier than polyester. All of the woofers
failed with tears where the foam takes a bend to the inner glue lip. I'd expect that eventually the
outer bend would also tear. I believe that they should double or quadruple the thickness of the
foam at those bends and/or make them a filled fillet type of bend. I've already done most of my
woofers but one could try running a bead of rubbery glue around those bends.
I don't fully recall since I've not looked at one in some time but I mention in the first post that the
foam felt weaker so perhaps this would not work.
I wonder if anyone has considered making these out of something like silicone caulk rubber?

 

[goodolpg]

Interesting thread.
Mostly beyond my feeble brain.
But I do work with caulk a lot.
Seems to me the weight of a "caulk" surround would be far heavier than foam. In addition, when dry the caulk would not have near the flexability of a foam surround. IMO.
That said, I wonder if a thin bead of clear caulk might help prevent the tears mentioned above where the roll begins and ends on a surround?
In addition is there a "treatment" available for foam surrounds? I believe there treatments for cloth surrounds, and supposedly some products work with rubber surrounds.

 

[nerdorama]

I wonder if coating with the butyl mixture sold for cloth surround restoration would help them be more immune from environmental issues. It stays very flexible and a thin coating wouldn't add too much mass.
John