Call or email Axiom directly and explain the situation to them. It sounds like there is something mechanically wrong with that lower woofer and we can't help you with getting replacement parts. The likely scenario is Axiom will ship you a new woofer once you talk with them and then you will have to swap the bad driver with the replacement.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne