I'm talking about the room listening environment that is about 7 meters from the speakers for normal sitting down listening.

I'm also talking about electronic crossovers, and separate amp for the tweeter array (and mid/woof, and sub woofer). I'm talking about cutting the flanges so that the distance is less that 1/8 of an inch between tweeter speakers, and well as between the flanges of the midrange drivers. I'm looking to cross them at 3000 to 3500 hz.

Another piece that I read (http://www.lenardaudio.com/education/07_horns.html) suggested that round horns were the most musical, and talked against constant directivity or rectangular horns.

eric j