1. If you where to build a 2x12" box would it be any advantage to make it into two separate 1x12" cabs inside the box? I´ve read somewhere that the drivers would affect eachother negatively if they where in the same box. This box within a box would probably make the cab really stable and more bracing might not be necesary. 2. Is there a thumb rule for how shallow a cab can be made? HiFi cabs are often really deep compared to the baffle width. 3. Is there any negative effect if using pine plywood instead of birch ply? The pine is much lighter and would be great on my back. Does the pine ply have to be thicker and therefore weigh as much as the thinner birch to be as stable?