There are a couple of things you can do. Pardon me if I get too basic but it is better to be that than miss something.
1.Check the leads from the console to the power amp, making sure + is connected to + and - is connected to -. Do this all the way through the chain up to and including the speakers. If all is wired correctly, fine. If not change the wiring.
2. Next, take a 1.5 volt battery and connect the positive of the battery to the positive of the speaker;connect the negative of the battery to the negative of the speaker. The speaker cone should push forward. Do this to both speakers. If both push forward fine, if not do both pull in? While the second case is not desireable, at least both speakers have the same polarity. If one pushes out and the other in, then there is something wrong.
3. Play a recording through only one speaker with it panned left or right. How does it sound? If it sounds OK then proceed to the next. If it sounds hollow, then I would begin to suspect the room. Do the same with the other speaker. Then pan one speaker center. Does it sound hollow by itself? If yes, it is the room. If not, it is the electronics.
4. Not knowing much about your room, I would be it is fairly small and that you have your speakers set up in the null of a standing wave. You might try moving your speakers slowly away from the listening position to hear if the bass quality improves. You might have to move them a few feet. There is a wonderful, free program from rpginc.com called the Room Optimizer. Download this and see if it leads you to an acoustic solution.
Barry