I've got two 20" wide, which are plenty for mosts gigs, up to 500 seats maybe, and two 30" wide that I use for up to maybe 800 seats, I use all four only for the really big gigs. I've got Magnum 15LFs in all of them. The 36" wide version would be for two fifteens, too much for even two guys to move around. There's a guy who has a pair of 36" dual 15s in his autobody shop, in California I think, he says that they can be heard a mile away at another shop owned by a friend of his. He's seriously nuts, plans on building two more.