imho, this will be the best design, both shown, or mentioned. not only more rigid with the "L" cut-out, but better driver spacing (from personal experience) what will matter a big deal, though, is the spacing from the ports to the rear gate. my understanding of how it works with the faced-firing drivers, is that the 2 waves compress in to a stronger focal pressure, resulting in a better developed, higher strength wave coming from the area, rather than mean cabin compression. i have also found the "sweet-spot" for the ports from 2-4" wide is 3 to 7" from the rear gate, sometimes as much as 9" when firing upward