You're talking about dispersion, directivity, and power response.
It's easy enough to spray the room with HF dispersion and generate a huge soundstage. What a listener hears at any location, however, is dependent upon what is being reflected back by the room, easily seen as being variably dependent upon the the reflectivity of the room itself and its contents. Drapes on one side and a blank wall on the other, and it's fruitless; you've got to construct and arrange the room as part of the speaker. I can measure the influence of the location of my coffee cup. It's the room we're listening to, not the program.
At the next level, and this is where AR's (and others') focus comes to the fore, is power response. Assuming uniform reflectivity, what the speaker is sending out must be uniform in two respects: first, the frequency response across the spectrum delivered by the several drivers must be smooth and flat, as a starting point, at least, and second, all of the drivers must exhibit the same dispersion pattern in their respective ranges, particularly in the mid and high frequencies, such that what is reflected back is similarly uniform at all angles. The Toole papers discuss this in detail; power response is easily quantifiable.
However, still relying primarily upon room reflections to generate the soundfield, we remain at the mercy of the room, and thus there is an enormous literature and industry devoted to the science of room treatments to "tune" the system, incorporating the room and speaker(s) in combination, to achieve the desired result. Another school teaches the opposite: forget all of that, deaden the room, design speakers with a very narrow dispersion pattern, aim them at the listener, and remove the influence of the room from the equation to the largest extent achievable, in effect, build big headphones, and listen from the precisely defined "sweet spot" between them.
There's another approach, and I hesitate to describe it as either a compromise or intermediate between these, because, though it incorporates elements of both extremes, it conceptually employs them differently: constant directivity. Originally developed and refined for use in performance spaces to control reflections and provide a uniform direct soundfield in indoor spaces like theaters and concert halls as well as outdoor venues, it may also be effectively deployed in our smaller listening areas to minimize the role of the room. Again, I refer you and other interested readers to the Toole papers, several of which may be found here:
http://www.harman.com/about_harman/technology_leadership.aspx
And to this Linkwitz lecture on the subject:
http://www.audiokarma.org/forums/showthread.php?p=2087949#post2087949
And Geddes, of course.
Many of AR's design objectives can be met with a $6 waveguide today without having to rationalize or conceal the facts.... :yes:
