Creating your own bass guitar cabinet is rewarding, but can be quite challenging. Bass guitar cabinets usually require the most materials and the most calculation in order to achieve a sturdy cabinet that can handle the low frequency demands of the bass guitar as an instrument.
Creating the Baffle and Frame
Measure and precisely cut out a square of 3/4 inch plywood with the dimensions of 31 x 26 inches with your circular saw or table saw. This will be the main baffle of your speaker cabinet where the speakers will be mounted.
Measure and precisely cut out two rectangular pieces of 3/4 inch plywood with the dimensions of 32 1/2 x 13 inches and one piece at 32 1/2 x 27 1/2 inches and two pieces at 27 1/2 x 13 inches. This will create the frame for your speaker cabinet.
On the first 32 x 26 inch cut of plywood you made, from the top right hand corner, measure one foot from the top and one foot from the right, trace a perfect 10 inch circle revolving from that point.
Measuring from the top left hand corner one foot from the top and one foot from the left, trace a 10 inch circle revolving from that point.
On the bottom right and left hand corner trace two 10 inch circles pulling 19 inches from the bottom and one foot from each side.
Below the circles, trace two 4 inch circles pulling 5 inces from the bottom and one foot from each side.
Cut out all of these circles neatly with a jigsaw or router saw just outside of the line to give a tiny bit of room for the speakers and port tubes. Spray paint this piece black.
Glue and screw together all sections of plywood besides the 32 1/2 x 27 1/2 inch piece that makes the back of the cabinet.
Cover the four sides besides the baffle in tolex by tightly wrapping each side like you are wrapping a present and stapling it off tightly inside of the cabinet.
Installing Speakers and Port Tubes
Set the cabinet on its back. Carefully place all 10 inch speakers inside of the four 10 inch holes in the baffle and attach them with the four speaker mounting kits.
Fit the two 4 inch wide port tubes into the 4 inch holes below the speakers and install them with the small mounting screws.
Cut four 18 inch lengths of speaker wire and attach them to the positive and negative contacts on each speaker.
Finishing Your Cabinet
Cut the appropriate rectangle shape needed to fit the speaker jack into the remaining back plywood piece. Wrap this piece in tolex.
Mount the speaker jack onto the back panel with provided mounting screws.
Attach each wire from each 10 inch speaker to the speaker jack and then solder it with a soldering iron. Screw the back panel onto the cabinet.
Attach four rubber feet or caster wheels to the bottom of the cabinet.
Finishings can be added to give your cabinet a more professional look, such as cabinet corners in plastic or shiny metal, sanding down the corners to create smooth edges, decorative piping under the tolex at each corner of the front of the cabinet and a frame that fits in front of the baffle covered in a decorative grill cloth.
Be extremely careful using any power tools; have someone help you feed sheets of plywood through your table saw to avoid kick back which could lead to serious injury. Always use safety goggles, gloves and ear plugs when using power tools.