box design help for 2 rockford p3d2

[Scalian]

I have one rockford p3d4 12 in a 1.8 ft^3 ported box with a alpine amp 575 watt per the birth sheet. Thinking about a new box with two of the subs at 1 ohm using a sound qubed 1200 x 1 amp. This would be going in a 2009 altima. help with the box design would be much apreciated. I know the first question would be max deminsions. Im thinking what would be optimal dimensions? Pretty sure anyting thing will fit in the trunk.

[wizart383]

What size is the driver ?

[Scalian]

12 inch driver, also updating the original post

[john253a]

Stick with 3.5-3.6net

Single 6" aero or 45sq" slot port

As far as amp

That amp is perfect for 2 p3, I even know a few with 3x p3 off it

[Scalian]

So i got my custom box built for my single sub and the sound is so much louder and better sounding I wont be doing 2 subs at this time. That being said someone posted on my thread for the single sub box design for help with two. So i thought i would give it a go and try and help him out and maybe learn some more about box design myself

Goal was for a 3.6 ft^3 net box

I figured the port at 14.5x4x30 for a displacement of 1 ft^33

Sub displacement of .388 ft^3 for two subs

Tuned at 34.5 per WinISD (was shooting for 34 but messed up the settings and didn't notice until i had the sketch up done and to lazy to redo it now. Should be fine to learn on)

One thing im not sure on is if i figured the port correctly. Port is 4 inches wide. I drew it leaving 2 inches from the back wall of the box to the port wall where it splits. I think this is correct as i have read it should be half the width in each direction. I left the lay out lines in the drawing for reference in the next question. I went back 18.75 inches at 4inches wide then went from the center line over 11.25 each direction to find the end of the port. Is this the correct way to get to 30 inches port length with a split design?

[irnlve]

antsy dance lol

[irnlve]

any luck w this yet?