Do you "treat" your speakers rubber surrounds?

+1 to mink oil or the 303 Aerospace Protectant.

Must admit I've not considered treating rubber speaker surrounds.  But since I'm restoring a pair of classic A-25s for the den maybe I should.

I have used a treatment called Rubber Renue by MG Chemicals on rubber belts for turntables, CD drawers, and tape decks and that seems to be beneficial.  I feel safe with that since it is formulated for rubber applications.

I used Armor All on a car’s dashboard cover.  It made it crack faster.  Then again, the dash is vinyl.  I imagine it would be worse for rubber.

I would be worried that anything that would soften the rubber would attack the glue that holds it on. Probably causing more problems then it would fix. 

The oils in the rubber will leach out no matter what you do. The best thing you can do is keep them out of the sun and heat. 

For what it is worth I have worked in the polymer industry for 15 years and designed a handful of elastomer products, though they are not my specialty. 

NO