Box design help

[412Mark]

I have a pair of hdc3-12s and looking for help on the box design. I'm pushing them with a sq-2200d. AMI suggests 3 cubes per sub with 18 square inches of port per cube and tuned to 34-39hertz for the older style subs I have on 1000 watts. I want to try it close to his suggestions but on the lower side of his tuning range. So I am looking at a box of 6 cubes with 108 square inches of port tuned to 34-35 hertz. The dimension I have is 15 3/4 high 33 3/4 wide and 32 front to back. Subs will be facing forward sealed off trunk. If any dimension could be smaller I would go with the front to back

[Joe X]

So here is a suggestion using your max dimensions, power: to subs rated, amp subsonic filter to 28Hz, minimum port clearance 7 1/2", figure is just an assembly guide, bracing is 1 1/4" wooden dowel rods:

NOTE: If building outside you need to build a cardboard dummy box to test fit in it's way inside.

[412Mark]

Looks like I can't get the full 6 cubes in my trunk I do want to upgrade my amp to the q1-4500 after I get my alt and my batteries to handle that much power. He does suggest a smaller box with a little less port for 2k a sub. How much a difference would 5 cubes with 85 square inches of port still tuned to the 34-35 hertz range make. I am hoping to have enough room behind the box for room for batteries. If it don't the only other option I would have is using the wheel well for more air space