Hmmm,
First question is- How did it get there? Abuse? Accident?
Couple of things you can try, depending upon the severity. Regular fingernail polish painte over the crack might be enough, but put on a couple of coats. With a sub, It may be a little trickier because of the movement of the cone. Also, you can try strips of regular electrical tape. maybe one piece on each side (front & back of the cone) run it well past the end of the tear on both ends. If that doesn't work, then try to find a reconing place around & do it right.
Good luck!
Will
Will Burleigh
June 2007