I asked about the back of the cone specifically and how it behaved in conditions were it might be exposed to water, moisture, and humidity. Nothing about the other parts of the driver or other environment concerns like dust or dirt.
The Nextel cone is Nextel coated paper on the front only. The back of the cone has a normal “doping” compound on it. It should be fine in moderate humidity but isn’t up to being immersed.
A definition for doping for those wondering like I was -
a. any of various varnish like products for coating a fabric, as of airplane wings, in order to make it waterproof, stronger, etc.
b. a similar product used to coat the fabric of a balloon to reduce gas leakage.