Right now I have two rows of 4 tweeters each artfully duct taped to the mid range horn bell lip. I would like to try to sound phase array the horn, and tweeters to the woofer as per some other thread. I can't remember, but I think that the tweeters are arrayed at 40 degrees from each other around the 12" radius. Maybe arrayed at a larger radius would be a better match to the tweeters dispersion angle. I will have to see if I can find that data.