Box design help.

[Mr Bigolsworth]

Started framing out my trunk to seal it. These are the max dimensions Base is 13.5 top is 9 height is 16 and width is 28. Could go wider but would like to put a battery in the frame if its worth losing the battery space I can so my max width is 36.5. Ill be running either the new type r 12 (1000watts rms) or a sa-12. I wanna port around 33hrz If someone could design me a box that would be awesome. Thanks.

From inside the car you can't see any of the framing.

[Joe X]

If you do the box narrow, it will need to be deep to meet the required net volume, or you can do it wide and your depth requirements will lessen, it could be done as narrow as 29" for the sa12s for a 16"h, also the swr12s have different net volume requirements, the sa12s box would need to be somewhat larger.

Also is important that you know what kind of sound are you looking for and what kind of power are you considering, for the sa12s about 2K power is what you can do, the Alpines will likely handle more than that, for that kind of power you will need electrical upgrades in both cases.

[Mr Bigolsworth]

I'm looking at running 1000watts rms to them. It an everyday use subwoofer set up for rap and dub step. What would u recommend tunning it to and could u please sketch me up a design for the sa-12. Ill be running 0 gauge from battery back to second battery. That's another reason I'm not going with two 12's so I don't have to do huge upgrades and keep my trunk space. I can go a little deeper too.

[Mr Bigolsworth]

If I go 16.5 hight, 9 deep and 36.5 wide my interior volume would be 2.20. Just don't know how to design the port and do that math for tunning.

[Joe X]

Ok for one SA-12 with a baffle of 16 1/2" x 36 1/2" I would suggest this:

*** Done on OPs dimensions but actually I wouldn't recommend the form factor of the following box.

Enclosure Specifications:

Fb = 33 Hz
Vb = 2.1 ft^3

External Height = 16.5 in
External Width = 36.5 in
External Depth = 10.5 in

Port Width = 1 3/4 in

Cut Sheet List:

* All Dimensions in Inches.
* Wood Thickness is 3/4 for all Parts.

External Enclosure Parts:

Front = 34 x 15
Back = 36 1/2 x 15

Left & Right Sides:
Side 1 = 9 x 15
Side 2 = 9 3/4 x 15

Top & Bottom = 36 1/2 x 10 1/2

L Port Internal Assembly Parts:

Front to Back = 7 1/4 x 15
Extension = 16 x 15

Assembly guide (generic dimensions):

Important notes:

- All trunk boxes built outside the car need to fit in their way in not just have the right dimensions.

- The port needs 1 3/4" of free airspace in front of it for proper operation.

- Setting your amp subsonic filter to 28Hz is suggested.

[Mr Bigolsworth]

Joe I need a design for a single sa-12. And if I do a sing,e can I stick with my original depth of 9 inches.

[Mr Bigolsworth]

Thank you very much for your help. Greatly appreciated.

[Mr Bigolsworth]

Hey joe I have the opportunity to get a dc lvl4 12 for a good price. Would this box work or would I need to start over?

[Joe X]

The motor becomes too near to the port wall in the back and the box for a level 4 is expected to be a little stronger, if the box is already done then add a second layer of MDF to the baffle, that will increase that clearance and make it stronger, also it will be working in a larger net volume than recommended which is only a problem if you are running a lot of power to it.

[Joe X]

BTW that's a nice upgrade