A 90x40 Constant Directivety horn has a Vertical polar pattern something resembling the following ( turn the horn sideways like the 1400 Array , this becomes the horizontal coverage ) ;
http://www.audioheritage.org/vbullet...2&d=1333987587
The following is a polar pattern for some wide dispersion CD horns, (as measured in the horizontal ) .
http://www.audioheritage.org/vbullet...1&d=1333987586
The first pattern exhibits a lot more "beaming" when compared to the second ( as defined by the 6db & 10db down points ) .
One can get a very similar ( though not duplicate ) "imaging effect" by simply using the older radial type horns ( in their normal orientation, since they also "beam" ) .
:)
PS ; Considering the ongoing interest ( & comparisons being articulated ) between the E2 and the Array1400 , it would interesting ( & enlightening even ) to see a comparison of their respective polar responses ( Horizontal, from 1K to 10K ) .