Digital Audio 12" subs

Ok heres the scoop, I have a '99 Ford Taurus with a Kenwood KDC-MPV7019 Deck with 4ga wire to a Profile California 800 amp and 12ga wire to 2 12" Digital Audio Subs. for some reason one of my subs does not turn on, they are both bridged, but when i removed it i checked to see if it scratched when i pushed in the speeker, it didn't so i reinstalled it, and then it worked again, but only for about a day, i have done this twice now and i have no clue whats goin' on. Any help??

loose coil wire connection.

could be a manufacturing defect.

take it back... try another one at the shop. Best bet.