It's hard to say this without sounding like an Axiom apologist, but they are certainly aware of conventional wisdom regarding center channel design, have even experimented with such designs and driver layouts, and have ruled them out by subjecting them to blind listening tests against other, less conventional designs.

This is how Axiom operates. In fact, the answer to the question "Why did Axiom design it this way when other companies do it that way?" is often "Because they found that way didn't stand up to this way in their tests."