hello i have an alpine type R 12" as the title states (SWR-1242D dual 4ohm to be exact) and have it in a sealed box, i am currently thinking of building or buying a ported box and am wondering what your suggestions for dimensions, port size, hz tune, etc. This would probably be done closer to the summer being as i now have other prioritys for wat im buying but wouldnt mind having all the information for when i do finalize plans, One more thing to add is if i buy and not build any preferred sites?