Okay, I'm not actually building anything yet, just gathering information. I'm still pretty green on the whole speaker spec thing, but I'm learning slowly. What I'm wondering is if you want to use two or more identical drivers in the same enclosure what happens to that "Vas Liters" parameter? Do you need to double that? I know there's 50,000 other issues to consider in speaker design, but basically I have a design in mind and I wanna know how big the box needs to be if I use multiple drivers.