Need box design help

[2010gmc]

I'm planning on building a ported box for my Rockford fosgate p1 12's just for the hell of it really. This is going in a 2010 gmc Sierra crew cab but I will not keep it in the truck all the time. I can go with about 36 for width, and about 32 for height but I think I can only do 20 or or a little less for the depth so that I can fit it in through the door. First of all I was wondering if I can fit a good ported box in there with those measurement and if I can I need help on the design because this would be my first box

[2010gmc]

Also they would be on 500 watts and I want them to get pretty low and loud but I want them to sound clean above all

[bbeljefe]

You have plenty of space for those subs in a ported enclosure.

What do you need help with?

[2010gmc]

Well I don't know what air space, tuning frequency, and a lot of stuff like that. I have zero real world experience with ported enclosures I've only seen them on the Internet. Also before this goes any further, I've heard a kicker in a prefab ported and there was port noise and it just don't sound good, but I could make these subs sound clean and with zero port noise right?

[bbeljefe]

Okay but, you haven't really told me what you need help with.

I don't mean to condescend but... do you know how to use a tape measure and a saw? Can you figure volume?

I need to know where to start with helping you and I don't want to start with telling you which end of the hammer to hold if you already know. ;-)

And yes, you can build a great sounding box. If all you've heard is a Kicker in a prefab, you've not heard anything. ;-)

[gr8handogoatness]

Are you using 2? If so you have more than enough space. As far was wanting good sound, sealed will be the easiest way to get you there. Plus if I remember tight I think the EBP is lower so it tends to "prefer" sealed boxes. If it has to be ported I would say 1.75ish cubes each tuned to the mid 30s. I'm thinking that's probably what rockford would say if you looked on the site. Actually, I'll go do that.

[gr8handogoatness]

http://www.rockfordfosgate.com/products/details/p1s4-12

Then click on "Box Advisor". It is as I thought.

[2010gmc]

The help i need is in the design of the box. I can cut everything and put the box together but I don't know how to decide what dimensions to build the box to, the dimensions of the port and which way to face them. I'm thinking facing up and port facing up because the box will be close to seats in the front and back because I will have the rear seats folded up. Also that kicker is the only ported box that I have heard recently. I know it's nothing. I did hear a rf p2 12 in my friends jeep liberty a long time ago that was ported and if I remember right it got loud, low and sounded good. And yeah I am using 2 subs.

[bbeljefe]

Subs forward and port up has been a good combo for me in extended cab trucks but you can do what you like.

I would do 2.25 cubes per sub tuned at 34 Hz with 16in² of port area. With your dimensions, that works out like this:

Box: 30w X 28W X 12D

Vent: 1.5 X 10.5 X 4 (center slot on top of box)

[2010gmc]

For those dimensions for the box and port are they width by height by depth?