Pile them on top of each other. Bingo you have a hi tech folded horn array.Or if you don't want to do that, then the only person I know of who could advise on how to do an array of folded horns would have to be Bill.
Essentially..... I have an array of sealed mid-ranges. Each one is a sealed separate speaker piled on top of each other. Same for the tweeters. Why would woofers be any different? I would never even consider putting any of the individual speakers in an array in the same enclosure, that's COLORATION LUNACY!
Marlboro