Building a custom box

[DarkScorpion]

I'm building a vented wedge box that will (hopefully) match the angle of the back seat and sit flush. The problem is, I'm not sure how to make the vent. Not about the length and width, but about the angle. A traditional square/rectangle box would just have the vent run along the side, but since this is a wedge, should I just run the vent along the side as if it were a square box and just match the angle of the back panel as well? Or would I be better off using a round port made with PVC or something of the like? I'd rather not go sealed, and I want to take advantage of as much space as possible. Any ideas?

[unique2.5]

i guess it partially depends on first are you putting in one sub or two..which leads to the basic question of how many cubic feet are you trying to give your box

[DarkScorpion]

Single Alpine 12" type R, aiming for 1.7-2 cubes, depending on what the final dimensions turn out to be. I want to tune the port to around 32-33 hz. I'm thinking I should just go with a flared tube port to save myself the headache of cutting the back plate of the slot vent to match the seat angle.

[unique2.5]

yeah i think that would be easier haha