I have a 1998 civic coupe and want to make a box for 1 -12 inch sub.Its a mmats pro p3 12 inch sub.Now their website says 1.15 cubic feet for a sealed box , I did the math multiply by 1728 but my demesnsions
height 12.57 , width 7.75 , depth 20.36
Doesn't the height seem close for a 12 inch sub?What are the measurements supposed to be?I e mailed them but since my sub is old they don't support it only the new ones?please help.

 

the12volt.com

That's what I use when I need to make a box. The volume you're describing is INTERNAL volume, not the outside overall dimension. You have to account for speaker/woofer displacement as well.

 

Thank you.Now in order for me to get my 1.15 cubic feet in a rectangular box my mounting depth is 9 inches but the mmats website says 6.25.I assume it can be bigger they are giving the dimensions of the sub?

 

6.25" is the length from the end of the magnet to the back side of the mounting basket. Most of the time, you need at least 3" of spacing behind the magnet to the wood material.

The total internal volume needs to be 1.28cu ft.

1.15cubic feet (recommended volume) + .13 (speaker displacement)

This box spec should fit:
16" W x 12" H x 16" D ---> 1.28 cubic feet.

 

I thought that, that the magnet would need room behind it.Thanks for the measurements but im confused if the height of the box is 12 but my sub is 12.5?
I came up with 14 height, 9 width and 23 depth.

 

12.5" is the overall diameter of the sub. The box needs to allow 3"+ behind the magnet.

In other words, it doesn't matter how wide or long the box is, just as long as you account for this, it should work. If the end internal volume is 1.28cu ft, that's all that matters.

 

Thank you.