You really have to build a 12π basshorn. It's amazing. I have seen and heard a lot of basshorns, and used outdoors, singles usually get a bit peaky or lose the deepest low end. But this one doesn't. It's deep and powerful, even in small numbers. Lowest distortion you could possibly have in the bottom octave, thanks to the push-pull arrangement and horn loading. And the heat exchangers keep it cool, so power compression is next to nothing. Really, not just talk. When you measure one of these things, the response at high power is exactly the same as it is down low, indicating that voice coil heat hasn't shifted electro-mechanical parameters. This is a no-compromize box.As for how many you'll need, that's determined by your venue, number of people and content. I've seen some large events that I think would be overkill with one or two boxes. I've seen others that need four or eight. Most sound companies that do big shows would have eight to as many as twenty. But if you build a pair of 'em, I think you'll probably have more than enough for what you need. It's a hell of a speaker, packs a whallop like nothing you've ever heard.