The ends of my VP150 are 39" away from my M80s. My M80s are 96" apart by the way and toed in. My centre has excellent "centre definition".

So, for his 120" screen, he can place the first VP150 23" away from the end of his screen. The second VP150 would be placed 23" away from the first.

The M80s could be placed 39" away from the edge of the screen. So he needs a 25' wide wall to accomodate all of this. This width includes 3' of space beside each M80 to the sidewall.

Does this make more sense?