prevent hardening of speaker surrounds

Well, if you are so interested in seeing this solubility table for Armor All, why aren't you asking them for it? Also, I did ask the speaker manufacturer specifically what their thoughts were before I applied Armor All, and they informed me that there would be no degradation of the rubber, and no interactions with the glue that holds the butyl rubber to the polypropylene cone. So you see, I took the only care that should have been taken, in my case. I didn't have to be a chemist to do it, either. BTW, the manufacturer is Dynaudio, and I feel that they might know a little bit more about speaker drivers (especially their own) than anyone who will ever contribute to this forum....and they have spoken.

According to the MSDS, the primary solvent contained in Armor All is Propasol P(a glycol ether). I won't bother listing other components. This solvent should be OK for butyl surrounds or epoxy(used in many adhesives - check with your manufacturer). However, it would not be safe for use on vinyl, acrylic, many polyesters(which also are used as adhesives), ethylcellulose, nitrocellulose, certain chloro or fluouropolymers(Saran or Kynar), or polyurethane. Do not use it on foam surrounds unless the foam is a polypropylene type. And make sure of the type of adhesive used to attach your surrounds. Also, keep it off your speaker's finish at all costs. These finishes are usually polyurethane or lacquer(usually nitrocellulose) based, and will be attacked by glycol ethers. Don't ruin that furniture quality finish you paid so much for in the first place.

Trelja; I want to thank you for your responses. Although I am not a chemist, I did get a minor in chemistry in college. I did not like the requirement of German for chem. majors and this was the rebellious 1960's, so of course I quit chem. Although there is no occidation occuring as yet, it is inevitable. The ozone in the atmosphere will see to that - as well as UV (a good reason to keep grills on). When you buy speakers as expensive as Aerial 10ts you want to keep them around for some time and in peak operating condition. It just seemed prudent to see if there was some way of maintaining the operating parameters of the speaker surrounds as long as possible. We audiophiles seem to obsess over things like jitter, green magic markers, pucks etc. that we forget that the suspension of a speaker is probably at least as important. Thaks again. mjdraper@earthlink.net

To clarify something, here, I agree that the suspension of the speaker is of paramount importance. However, it's the rear suspension on cone speakers (the spider, a woven fabric) where the primary burden lies, with respect to how the cone behaves, since it is connected to the "balanced center" of the moving mass of the diaphragm. The front "surround" serves primarily to keep the cone centered during motion, and serves an extremely minute roll in the "suspending" of the diaphragm's mass. Therefore, changes in sonic performance over time are due to changes/wear in the spider, and not so much from the front surround. SUBARU ALLUDES TO THIS ABOVE.

I agree 100%. The part we don't see(suspension) is where is much more critical. I also know that speakers with different surrounds(foam, linen, butyl, etc.) sound different. Neither point was the issue in this thread, however. Appreciate your perspectives Carl, and your compliments Mjdraper. Thanks to both of you!