I personally use a 2way array crossed at 80 Hz to my Tuba 18 mini horn loaded sub. In my case the sub came first, and it so dwarfed the sound of my previous MTMs that I built the arrays to have something that could keep up with the SPL of the sub. As to which way to go, both a small horn loaded sub and an array of woofers will give the requesite SPL, but the horn loaded option is far smaller, unobtrusive and cheaper. If you do array you won't need tens to do it, investigate 8s, and look for closeouts. Save $ buying woofers with low wattage and xmax since you don't need much of either when using a lot of them.