May not be an issue, but for anyone building a clone, you might consider rotating the mounting holes for the woofer a bit (22.5 degrees, I think). The reason is that upper and lower T-nut is right where the diverters (ramps) are, and any excessive screw length used for woofer mounting will impinge on the diverter joint. If you clock everything it ends up putting the T-nuts where they won't hit the diverters at all.