Thanks for the additional feedback.  Agree that there is at least some equalization going on with the amp... probably high-pass filters to keep from damaging the small Bose drivers.

This installation has three different style Bose speakers including some landscape speakers that I expect have larger drivers so was kind of surprised the amp didn't have some way of defining the speakers.

It's likely possible to swap out some of the speakers with something more conventional, but there are a few areas where there just isn't much room for anything larger.  I'd have to remove each speaker to feel around in the walls and ceiling for framing to see what's possible.