JBL 4311 12"

[cool9]

I bought these a week ago and there is some white stuff on the 12" surrounds which I can't explain. The stuff won't come off. The speakers sound fine. Any idea? Mold?

 

[L200B]

I have had like 10 pair of these Bs in the last couple years. That isn't something I have seen before. Maybe someone resealed the surrounds with something they shouldn't have.

 

[swechsler]

My guess is that they were stored in a moist environment. The random distribution makes me think it's some form of mildew. If that's what it is, the cure will probably be worse than the disease (i.e. any cleaner you used to dissolve it would have a decent chance of damaging the surround coating) - you're best off leaving them as-is unless it can simply be brushed off, but I'm guessing it can't since you probably would have tried that already..

 

[Zonker92]

You might try a black Sharpie on one small area to see what happens.

 

[L200B]

I'd use black paint. Very very lightly. Black sharpie drys kinda purple.