Making your own 2X12 guitar speaker cabinet will not only save you money, but it will allow you to customise your sound with the use of different types of speakers and configurations. By making your own cabinet, you can experiment with different wattages and brands of speakers. Use it as an extension cabinet for an amp, or as a stand-alone cabinet with a guitar head in the studio, or for live shows.
Cut the wood for the 2X12 speaker cabinet. Using a table saw, cut two pieces of MDF or plywood to 26 by 14 inches for the front and back of the 2X12 cabinet. If you want staggered speaker placement, cut the pieces to 26 by 20 inches. This will result in a taller cabinet, which will be easier to hear if that is your only cabinet on stage. Cut the top, bottom and sides as well. For the side-by side configuration, cut two pieces to 26 by 12 inches, and two pieces to 14 by 12 inches for the sides.
Rout the front piece of the cabinet. You want to use a compass to assure that your speaker routes are perfect circles. Find the centres for each speaker and use the compass at 6 inches to create a 12-inche circle. Rout each speaker hole by drilling a hole to place the router or jigsaw, and cut carefully on the inside of the circle line to assure that the hole is not too big. You can use a sander or file to bring it out to size if it is too small.
Rout the back of the cabinet for the speaker jack. Draw the shape of the jack onto the wood and rout out the area so that it sits flush to the wood.
Construct the box frame for the cabinet. The frame consists of the top, bottom and sides. Glue them together and allow that to dry. Nail the area where the wood meets to strengthen the frame as it will help support the weight of the front and back, including the speakers.
Glue and nail the back piece onto the frame. Make sure there are no gaps and fill them with epoxy to seal the cabinet. If air escapes while playing, it will affect the sound negatively.
Attach the speakers to the front piece in their respective routes. Attach the wires to the speakers so that you can wire them after you have attached the front to the cabinet so far. Glue the front to the rest of the box and nail it where the wood meets after the glue has dried.
Wire the speakers to the jack and screw the jack into its spot on the back piece of wood. Use the wood screws that came with the jack and make sure it is wired according to the manual before screwing into place.