From the reviews, and Mr. Atkinson's comments, it appears that the tweeter's lateral dispersion ameliorates any possible problem.

It will be fun to learn what more people think when they get a chance to hear them.

Quote:
I am however a bit worried about the response above 10Khz in the measurements you published. On Fig 4 (http://www.stereophile.com/floorloudspeakers/307piosex/index4.html) there are very serious dips and peaks (-10dB to +10dB).

These are interference effects resulting from the coaxial arrangement of the tweeter and midrange unit. Basically, the output of the tweeter is reflecting from the boundary between the edge of the midrange cone and the surrounding baffle and because this distance is identical in all directions, the interference is maximized. However, both the position of the peaks and dips and their amplitude are very much dependent on the exact listening axis and the frequency region where all this is happening is higher than with some other designs using a coaxial tweeter/midrange unit. Both factors will tend to work against there being an audible problem.

John Atkinson
Editor, Stereophile