Speaker Rubber Seperating from Cone

i have Alpine SWR-1241D 12" subs and today i noticed that i heard a rattling comming from the back of my truck. i look back there and i notice that one of the speaker had seperated from the outer part about 2 inch long. Why does this happen? Too much Power? Defect ? Enclosure?

i have 4 of them powered by 1 Phoenix Gold Xenon 1200.1 should be able to handel the 300 watts given to them apiece.

thanks for the input........

The surround can seperate for many reasons including the ones you listed.  If it's under warranty take it back for replacement.  If not, you can have it repaired at any speaker re-cone shop.

What type of enclosure do you have them in?  Small sealed?  Large sealed?  Ported?

If large sealed or ported your power handling capability will be dramatically reduced.  The stated 300w per driver will suddenly become too much in those type of enclosures.