Instructions

• 1). Choose the right subwoofer for your home. After purchasing your subwoofer, look at the manufacturer's manual to see what size subwoofer box will give you maximum performance.
  
  
• 2). Design your subwoofer box. Measure the subwoofer depth and add 2 inches to find the minimum depth your box can be. Measure the diameter of the subwoofer or check the owner's manual to find the minimum height and width requirements for a subwoofer box.
  
  
• 3). Use the dimensions you just measured to sketch a preliminary drawing of the subwoofer box and decide what shape you would like it to be. Generally, subwoofer boxes are either rectangular or square. Find the box's internal dimensions by subtracting the thickness of the wood from the external dimensions.
  
  
• 4). Adjust the internal volume as necessary to best accommodate your subwoofer. Once you have finished all changes to the internal volume, add the width of the wood back to the internal dimensions to get the new external dimensions.
  
  
• 5). Use your dimensions to draw a pattern on the medium density fiberboard (MDF) and cut it with a table saw. You should cut seven pieces -- a top, bottom, back, two side pieces and two front pieces.
  
  
• 6). Use a compass to mark the subwoofer circular shape on one of the front pieces. Try to center the circle in the front piece. Use carpenter's glue to attach the two front pieces together and secure them with sheet metal screws. Drill a hole on the inside edge of the circle you drew on one of the front pieces. Drill a wide enough hole to accommodate your jigsaw blade. Insert the blade and cut along your pencil marking.
  
  
• 7). Use the same technique to cut a rectangle out of the back piece to accommodate the speaker terminal cup. Put a line of caulk on the terminal cup and insert it into the hole you just removed. Screw the cup in place with sheet metal screws.
  
  
• 8). Drill holes in the MDF board for the sheet metal screws that will be used to assemble the subwoofer. MDF board is fragile and can split if you insert the sheet metal screws without pre-drilled holes. Assemble the subwoofer by attaching the front and back to the sides, then attach the top and bottom. Use a generous amount of carpenter's glue between the pieces before securing them with the screws. If the subwoofer box is misshapen after you are done assembling it, correct the shape with a furniture clamp.
  
  
• 9). Place the subwoofer in the box to ensure it fits. If the box is too small, use sandpaper on it until the subwoofer fits snugly inside. Remove the subwoofer and pre-drill holes for the screws that will mount the subwoofer to the box.
  
  
• 10
  
  Caulk the inside of the box before placing the subwoofer back inside. This extra layer of caulk will seal the seams more effectively. Allow the caulk to sit for 12 to 24 hours to ensure it is completely dry. Stain, paint and decorate the box to your liking.
  
  
• 11
  
  Thread the speaker wires through the terminal cup and reinstall the subwoofer in the box, using sheet metal screws to secure the subwoofer. Hook up the subwoofer and test it.