For cornerhorns, you'll want about three feet of unobstructed wall space. Since you're planning to use the Altec 414's, please use the cabinet dimensions I sent to you via. E-Mail. I'll send plans for the Stage Series six π, but you'll want to make the cabinet slightly larger and use port dimensions as described in my letter.PiAlign recommends 1.6 cubic feet tuned to 56Hz for the Altec 414. This is a fairly small cabinet, but response looks great with -3dB point at 60Hz and -10dB at 45Hz. Cabinet dimensions should be 29 x 16 x 8.5 with a rectangular port having HxW dimensions of 2.875" x 5.125" and 4.0" long.