Build or buy new ported sub box for 1 new p2d2 12?

If you compare the box requirements for the Rockford P2D2-12 you're opting for there's not much advantage to the switch unless you are desperate to get the .3 difference from it's minimum recommended sealed enclosure. It's maximum recommended sealed is .01 cubes. A iota of a difference from it's recommended vented enclosure. Keep in mind the minimum sealed will not be the optimum size enclosure for low end. This may not be significant depending on where your vehicle's transfer function kicks in, but transients will be worse compared to the larger box. IE it will put more thump and upper bass in it's response that may not be so easy to get rid of whether using a EQ or steep crossover. Once it's there, it's pretty much there.

I'm not sure exactly what your goals are by the switch or the use of the ported box you linked that increases the amount of space currently used. The most you can do is switch to a truck style box that is not as deep, but wider. The total dimensions does not change, just the shape which my help. If you are looking to go smaller than what you have then you will have to opt for a different type of sub that uses micro enclosures. Something like this that only requires .5 cubes minimum and .75 max sealed. Wired in parallel the amp will have plenty headroom to stay clean and not stress. Just be sure to set the gain properly and not use any bass boost. It's better to have extra power than it is to have less.

Sonicelectronix also has a good list of prefab boxes to choose from. Just be sure to shoot some extra brads through the joints and add some extra glue in the seams to insure a good seal. Very economic in my opinion!

http://www.sonicelectronix.com/item_27304_RE-Audio...

http://www.sonicelectronix.com/viewcat.php?categor...

Not sure of the specs of your L7 since you haven't posted the model # so you will have to compare the two for yourself.

If you already own the proper tools, i.e., skill saw at least, power screw driver, drill, tape measure, jig saw, etc., then you should have no problems building your own box. If you do not have the tools, then you're probably better off buying one.

they're not that difficult and the materials are not that bad either. A full sheet of 3/4" MDF will run you $30. You can build several boxes with that if you don't waste your wood.

the headakes involved and the cost of the right lumber,and time your best bet is to buy a built en closer that is as close to the size recommended by the sub woofer manufacturer.this would be the way to go.and go to rockford fosgate.com/rf wiring wizard,this is a site that will give you the best way to wire your sub woofer.good luck with the little ones.

we did 4 8s in a wrnagler before in a vented cabinet.. get 4 4ohm subs and wire em down to 1 ohm...

Don't Build one.

It will not be tuned correctly.