How to Build the Right Size Box for My Subwoofer

By Nichole Liandi

For a subwoofer to operate properly, it must be installed in the correct size of enclosure. If you're a car audio hobbyist who's interested in making their own subwoofer box, you need to build your box to ensure the correct air volume within the box. Fortunately, it's not too difficult to make sure that the box you build is the correct size.

Things You'll Need

  • Subwoofer manual

Step 1

Find recommended volume specifications for your subwoofer. This will be listed in the subwoofer's manual. If you can't find it there, check online--most manufacturers will have manuals and specs listed there. The spec will be listed in cubic feet.

Step 2

Sketch out some sub box designs that take into account the space you have available for your sub, i.e., the trunk of your car, the space behind the seat. These sub box designs need to accommodate the dimensions of the subwoofer as well. Consider the size of the sub's cutout and the depth of the speaker.

Step 3

Multiply the dimensions, in inches, of the box you've sketched out. Multiply the depth, width, and height of the box together and then divide this number by 1728. The resulting number is the volume of the box in cubic feet. Compare this to the specs for the subwoofer. If the cubic volume fits within the range specified by the manufacturer, your sub will perform very well in your box.