The problem is something called comb filtering due to the tweeter elements being too far apart. You won't like the sound of anything above 3000 hz. It will sound awful.

Read Jim Griffin's white paper on line array design:

How comb filtering sounds

Comb filtering will dull the highs and will be most noticeable in the lack of air (dull highs) especially as you move off axis. Essentially, the high frequencies are rolled off as the ensemble of the tweeter outputs don't add up but start to cancel. Now the ear is less sensitive in the upper octave (10-20 kHz) you may not observe the full impact of this effect. But if you compare to an array that is properly designed, then there is no comparison as the proper array will yield a more airy (and accurate) sound.

Jim Griffin on PE(Parts Express Forum) 11-21-06