Cut the back and front pieces for the speaker box from large pieces of fiberboard. Fiberboard is perfect for an application such as this because of its high density and ability to minimize vibrations. Two 10-inch speakers are standard in many boxes, so cut your front and back panel to 24 by 12 inches. This will allow for two 10-inch bass-specific speakers.
Cut the sides of the box. You can cut two pieces of fiberboard to 12 by 10 inches. This is ample depth for the 10-inch speakers and will provide sufficient room within the closed box for the bass frequencies.
Cut the top and bottom of the speaker box from the fiberboard to 24 by 10 inches. This will be the only size that works and assures that the box is fully sealed to provide the tightest bass response.
Rout the speaker jack hole in the back piece. With a pencil, draw the shape of the speaker jack directly onto the fiberboard and drill a hole large enough to accommodate the jigsaw blade. Cut around the pencil lines to provide a hole for the jack.
Create the frame of the box by attaching the sides to the back piece. Glue one on each side and secure them with small nails. The glue will keep the wood together and provide a seal, while the nails will make sure the wood stays attached.
Attach the top and bottom pieces after the glue has dried on the sides and back of the speaker box. Also use glue and nails to secure and seal the box. The only piece missing should be the front at this point.
Draw the templates for the speakers on the front fiberboard with a pencil. Drill two small holes on each circle and rout out the holes for the speakers. Make sure to not go past the line you have drawn or the hole will be too big for the speaker.
Attach both speakers in the front piece with the included wood screw. Wire the speakers with enough wire to reach the speaker jack located on the back of the box.
Attach the front piece with the speakers onto your mostly completed wood frame. Nail it into place after applying glue along the edges to ensure a tight seal on the entire box. When air is able to escape, the tuned frequency of the box will change dramatically.
Pull the speaker wires through the back hole and attach to the speaker jack. Place the jack in its spot and screw in with the included wood screws.
You can remove the speakers and jack and paint the box or cover with enclosure carpet using a spray-on adhesive. Once you have finished the box, test it with an amplifier to see if both speakers are working correctly.