Does sound like the driver is blown.
+1 That's what it sounds like to me.
I have a 2 12" w/tweeter Avatar and I really like it, although I had a damaged speaker when I first bought it too. It had a frequency issue, B notes played anywhere on the neck rattled like crazy. The guys at Avatar took care of me with no hassle
Avatar uses woodscrews to mount the speakers, which is a pretty lame way to do things. If you're going to be in there swapping out a speaker, I would highly recommend opening up the mounting holes and putting in some T-Bolt anchors. It's not that much trouble and it's really worth it. It will give you a rock solid , rattle free cabinet .
Their stuff is very well designed and delivers great sound , but those wood screws are one of those little things to keep the cost down that I just plain don't like. The tweeter is nice, but it is wise to keep the volume on it it away from the wide open position or you will likely blow it too. That is not strictly an Avatar issue , I would be cautious with any tweeter cab.
Good luck
Rick