Assuming the speakers are fully broken in, this it the type of thing that happens when you don't take the time to match your components. When dealing with a speaker that is capable of revealing a lot of detail, especially when metal drivers are involved, its not good enough to just have enough power. You need to experiment and try different combinations of components to be sure that you know what you are getting into. Since you already have the speakers, I would see if you have some friends that can lend you some different equipment to try. Anything to see if you can move the sound in the right direction. I would definitely not buy anything new until you figure out what the problem is.
Also, you may want to list your system. Maybe you have an obvious bad match that someone may pick up on.
Also, you may want to list your system. Maybe you have an obvious bad match that someone may pick up on.