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I keep reading about refoaming and reconing speakers, and I would like to explore this activity with others. I have seen several speakers with the foam surrounds cracking and missing. Clearly this material has long-term reliability problems.When I look at used speakers to buy, I tend to eliminate anything with foam surrounds for this reason. I have bought a lot of Klipsch and Altec stuff (K-Horns, Model 19s) partly because they have accordian fold woofer surrounds (cloth?) that seem to hold up well. Or, I will do rubber surrounds that seem not to have rotted or come loose (KEF and some others).
My real question is whether these refoaming jobs have a chance of being a fully accurate, correctly-functioning replacement for the originals? I think, if surrounds from the manufacturer of the speaker are available, and the reconer is factory trained or highly experienced, it may be possible to get a factory-equivalent refoaming job done. I wonder though whether the materials, especially the foam itself, that is sold will fail quickly no matter how well the job is done due to age. Third party, Parts Express-type, kits seem to me unlikely to restore factory-designed conditions.
Perhaps I am being too exacting. Restoration of rotted out surrounds will restore some kind of performance to be sure, and maybe that's fine for many listeners.
I have similar questions about reconing. How can one be certain the cone material is identical to that being replaced?
Edits: 07/23/16Follow Ups:
A shootout between a re-foamed speaker and one that has had the elements replaced by OEM (or repaired by OEM) units would be interesting.I wonder if the huge cost difference would be justified by the OEM replacements sounding way better? Or if there would be no difference?
Edits: 07/24/16
i too prefer cloth surrounds or just pleated paper, but there are a lot of amazing drivers from the late 70's that used foam surrounds, mostly a manufacturing choice(not sure why),sadly most of them just crumble by 20 years or less
i have reconed many speakers and changed many surrounds anything under 8 inch could be done without shims in the vc , the larger ones need shimming to prevent rub
the key is patience,and the right tools ,appropriate glue,cleaning materials etc and doing this is very satisfying as you can get some very good speakers for nothing
as for surrounds ,there is a difference its the thickness of the foam and also the internal curvature of surround as when its glued back at an angle you need to avoid small creases and places that the glue does not hold properly
some surrounds are glued from the back of the cone.
for most of the Scandinavian drivers of yore i prefer the European foam suppliers,for the American drivers there are many us suppliers
i learned this the hard way as some of my refoam drivers would raise the spider and some were too thick and altered the fs
so research and have fun
for European drivers my favorite place is linked
For the most part, foam is foam. It's light enough so that the mechanical impedance of the driver is essentially unchanged.
My recommendation to anyone wanting to learn to refoam speakers is to:
1. Watch several youtube videos on the subject.
2. Buy a pair of cheap speakers at Goodwill or a yard sale and refoam them. Your second pair, the pair you care about, will come out better and be quicker to do.
Until I bought an Atlantic Technology subwoofer. The foam seemed to be impregnated with silicone. It was thicker, seemed more pliant, and I doubt will ever need replacing. It is already 30 years out, but is in perfect shape. Normal foam seems to last about 15 years. II would never switch the surround material, I think it changes a drivers dynamics. But some rubber ones
do seem to last forever..
I know one place I am going to do it and that's in my car. Lexus in their "pursuit of perfection" thought it would be a great idea to use a subwoofer with a foam surround then place it on the rear deck where it gets bombarded daily by sunlight. This gives the surround an effective lifetime of around 3 to 5 years.
It seems the new owners of the Mark Levinson name hired the accountants that work for Bose, but kept the designers that worked for Levinson. Because there is very little to fault in the design of the system in my 2006 LS430. But the speakers look like they were sourced from 1980's TV sets. And just in case we get uppity and try to replace the stuff with non-OEM, they made sure they all have crazy impedance numbers assuring that a typical 4 ohm car speaker will quickly ruin the amps.
So.... I'm going to find a bunch of nice sturdy rubber surrounds and replace ALL of the foam with rubber. The door midrange units also fail regularly at about 5 to 7 years. The tweeters are in the dash and I really don't know if they will ever get replaced! Thankfully, they seem to last a long time.
George,
There are a number of factors that cause the surrounds to deteriorate - Chief among them is the effect of the atmosphere - and the increased ozone on the original foam that was often used. This is similar to the deterioration of capacitors in a pre-amp or crossover. The materials from 20 or 50 years ago are different or the original choice was a compromise and now the components need attention-
as to the art of re-foaming - Yes it requires some skill and patience - but not a life-times worth.
For me - in the midst of replacing the surrounds on my ProAcs (new in 1994) the replacement is my only option as I can not afford to replace the drivers...
I anticipate that the results will be excellent -
Happy Listening
I replaced the foam surounds on a pair of Audio Note speakers a few years ago with excellent results. The foam surrounds were sourced directly from Audio Note and I followed the instructions they provided. Audio Note provided personal guidance on a couple of details via e-mail and I also received a couple of good tips by AA members. The key to success is to plan carefully, have the right tools and materials, take your time and work carefully. It may seem daunting to someone doing it the first time, but it is easier than you may think.
You dont have to be identical. Also DIY will have fine results for most. My first pair, some ARs I did around 1980 to use as car subs turned out great. An LF frequency sweep, which was the area I was going to use them in and is also the area which would show problems if they existed showed it very close to original spec with a basic SPL meter which itself is not 100% accurate. It will be fine, take the plunge, have fun. Its a good way to get speakers very cheap.
ET
"If at first you don't succeed, keep on sucking till you do suck seed" - Curly Howard 1936
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