Okay, this helps! Sort of how a rod op dowel, when upright, can support a very heavy object, but if the same rod or dowel were horizontal (supported at both ends only) and the heavy object were tied to its middle, it would bend or break? Air inside a sealed box presses outward and sucks inward nearly equally in all directions, and it would seem the mechanical energy in the material from the driver would seek the same paths of dissipation; that is, perpendicular to the long plane of the material. So, rods or dowels for bracing would be a low material volume, high rigidity bracing solution that would work quite well. Am I on the right track there?