I saw a interview with a Dynaudio engineer and he recommendsled treating speaker surrounds with a product called Sonax... It was like $15 on Amazon, I used it on my surrounds and it worked great, my speakers are pretty old and the rubber was getting a little dry, now they soft and shiny and very pliable, it did improve the sound too.
Sonax is from a German company, it’s for restoring dried out rubber on vehicle door seals I think, but it works great on speaker surrounds... I was just careful not to get it on the area where the rubber meets the woofer cone just in case it would cause the glue to fail, but I don’t think it would, I was just being extra careful. I cleaned the woofers first with a damp cloth and dried them.
Sonax is from a German company, it’s for restoring dried out rubber on vehicle door seals I think, but it works great on speaker surrounds... I was just careful not to get it on the area where the rubber meets the woofer cone just in case it would cause the glue to fail, but I don’t think it would, I was just being extra careful. I cleaned the woofers first with a damp cloth and dried them.