I want to build a box for 4 12" alpine type-Rs, but i want it build to alpine specs i dunno how do add the specs they give your in order to be built to alpine specs for 4-12si also wnt it ported braced 45 corners also. please halp i have no idea how to do this stuff or at at least someone can tell me what to do to have it built to speacs and 4-12s. Thanks!