Once you've mastered the basic box construction techniques, it's time to kick your creativity into gear and add some finishing touches. After building an enclosure to hold an Alpine 10" sub, I checked in with Crutchfield's installation specialist, Warren Hawkins, for some inspiration and installation tips.

Carpeting your subwoofer box:
Carpet is an economical and easy-to-apply box covering. Most prefabricated boxes come carpeted, and you can use carpet to achieve a very professional look on your custom-made box, too. Box carpet comes in quite a few colors (you can probably find some that will closely match your car's interior carpeting). Box carpet is available here at crutchfield.com and from upholstery stores.

To apply carpet, all you'll need is a utility knife, staple gun, and adhesive. 3M spray adhesive is an excellent choice; simply spray it on the back of the carpet and onto the box, allow it to dry until tacky, and then adhere the carpet to the box. Pop a few staples in unobtrusive spots — it'll help make sure your carpet stays firmly in place.

If you plan to carpet your box, we suggest that you use a special construction technique. Inset the left and right sides of your subwoofer box just a bit, so that you end up with a protruding edge all the way around both sides. (Remember that this technique will reduce your box's internal air space slightly, so account for that in the design).

When carpeting this type of box, wrap and glue the carpet from the front, back, top and bottom around the protruding edges, and use a utility knife to trim the material flush with the inside corners. Then, cut pieces of carpet to fit the insets — glue them in place, and again run your knife along the inside corners. With this technique, the two pieces of carpet will meet each other perfectly, and you won't have any raw edges or lumpy corners. Many prefabricated boxes are made this way — this box from Q-Logic is an example.

Note how the carpet on this box runs flush around the side insets.