I just got a nice used speaker cab shipped to me. Checked it out and it sounded like crap. Took off the grill, did the 9V battery thing, and only one of the drivers moved. Tapped on them both, and again only one thumped back. So I took out the 'bad' speaker, it felt like perhaps some of the insulation was jammed against the cone and not allowing it to move. No such thing. I then pushed on the cone, and it would move, but it's not floating, there is a lot of resistance. What's the problem? Could this have been damaged during shipment? Thanks folks.