Loctite 495 seemed to work alright for my brothers sub, but we just glued it today, so no telling if itll dry out the surround.
http://www.partsexpress.com/pe/showd...number=340-076 that should work alright too I would think.
Also, I have heard a lot of epoxys work well, but I am not too sure. You just want something that will be gentle on the rubber/foam surround, and that wont dry it out or eat through it or anything.
Good luck with it! And even if the surround rips, you can still get a new one. Just take it to a JL dealer to get it fixed, or find a place to buy a new surround.