I made a 2.8 cubic foot box tuned to 36 hz for my l7 that i got rid of that, sounded like garbage (even in the kicker designed box i had for it) and decided to get rid of it. Now I have a ported box with a square cutout. I was thinking of just putting a big piece of wood over it and screwing/siliconing/and gluing the heck out of it make it strong. I used 5/8 13 ply baltic birch (the 5x5 sheet) and can jump on the box no problem due to internal bracing. The dimensions of the box are 30 x 15 x 13 3/4 and the port is 2.75x12. What subwoofer would work best for the box I have?
Also another questions is where is the best place to put the su. bwoofer in reference to the port, closer or farther away from the port (since the port is front facing with the sub)
That enclosure is too big for the Alpine or the Sundown. I would sell it to someone with a Solobaric and build an enclosure for the sub you choose to go with. Otherwise it's just going to piss you off. With that kind of room to work with you could do a pair of SA-12s, a pair of those in 3.5 to 4 cf tuned to 30 hz will be extremely beefy.