Low end frequencies of 50 to 200hz, commonly called bass frequencies, are difficult to work with. Special equipment is used to raise volume and enhance clarity. Bass bins accomplish increased volume and clarity of bass frequencies by reflecting the sounds inside a box, or "bin," before sending them out to the listener. Bass bins are a common DIY project to improve live sound or home theatre audio quality.
Label your plywood boards with a pencil. Label the two 22-by-22-1/2 inch plywood boards A and B, the 20-by-21-by-1/2 inch plywood board C, the 15-by-21-by-1/2 inch plywood board D, the 10-by-21-by-1/2 inch plywood board E, the 34.6-by-21-by-1/2 inch plywood board F, the 22-by-18-by-1/2 inch plywood boards G, the one 40-by-22-by-1/2 inch plywood board H and the three 40-by-22-by-1/2 inch plywood boards I, J and K. Labeling the boards keeps them organised and simplifies the construction.
Mitre the edges of boards D, E and F using a mitre saw. Mitre one of the 21-inch edges of board D to 30 degrees and one of the 21-inch edges of board E to 15 degrees.Miter one of the 21-inch edges of board F to 30 degrees and the other 21-inch edge to 60 degrees.
Put a hole into board G 8.5 inches from one of the 21-inch edges and 11 inches from one of the 18-inch edges using your power drill. Draw a 15-inch diameter circle on the board radiating out from the hole you drilled using a protractor. Use a jigsaw to radiate out from the hole you drilled and cut the circle you drew from the board. The result is a 15-inch diameter hole in board G with 1 inch at the top and 2 inches at the bottom and 3 inches at either side.
Apply wood glue to to the mitred end of board D and clamp 2 inches below the hole on board G, creating an interior obtuse angle of 150 degrees between parts D and G. Apply wood glue to the mitred edge of board E and clamp to board D creating an acute interior angle of 85 degrees. The result should resemble a fishing hook or the letter "J." Set aside for two hours as the glue dries.
Apply wood glue to one of the 21-inch edges of board C and clamp to the centre of board A. The edges of board C should be exactly parallel with Board A and resemble a capital "T" when viewed from the side. After the glue dries, secure the boards with 1-inch wood screws using your power drill.
Create the box to house your bass bin by gluing boards I, J and K to board B and clamping each board in place. Glue I and J to be parallel and rest on top of board B and board K should create the back of the bass bin. One side should remain open. After the glue dries, secure the boards with 1-inch wood screws using your power drill.
Apply wood glue to the edges of board A on the side board C is fixed to and create the top of the box by laying board A glue-side down. Board C should be inside the box. Allow the glue to dry and secure the boards with 1-inch glue screws using your power drill.
Apply wood glue to the edges of board G and affix it to the front of the box, between boards I and J and beneath board A. The "hook" of the structure should be placed inside the box to reflect sound. Secure the boards with 1-inch wood screws using your power drill.
Apply wood glue to the mitred edges of board F and place in the interior bottom of the box with the 30-degree mitred edge placed against the bottom, board B, and the 60-degree mitred edge against board K, the back. Fix the boards in place with 3/4-inch wood screws using your power drill.
Look at some plans for other bass bins on the Internet before starting your own. The final board can alternatively be curved to get a little more clarity, however the exact curve must be very precise and is often not necessary. Primer and paint your bass bin for style. While not required, you may add support struts to all floating boards on the interior of your bass bin.
Always wear work gloves and goggles when using power tools, especially saws.