I'm planning on building my first ported box soon. It will be for 3 jl 12w1s. I plan on making it a slot port about 4.7 cubes at 28hz. My question is about port area. The design I have now has about 74in of port area. Would that work or will I end up with port noise? More? Less? I'm still learning about designing enclosures so anything else I should consider? First post, BTW. Thanks.