Sorry, I just looked at this thread. I have repaired hundreds of speakers, here is a quick fix. Remove the woofer. Cut a piece of thin fabric to fit in the surround area and cover the slit from the rear of the woofer. Now find some old paint. Carefully open it without shaking it at all. Spoon off of the top a tablespoon or so of latex. Mix the latex with an equal amount of elmers glue all. Soak the fabric in this mix, then place on the rear of the surround. Turn your woofer over(top up) with one hand on the rear, position your cloth, while watching the front to pinch close your gash to cosmetically show the least damage. Once you get it set, let it it dry 24 hour before playing. It should hold up fine.
Good luck, Tim
Good luck, Tim