Add a sub box to your Dodge Ram truck to get great bass from your aftermarket stereo system. If you want a great sounding stereo, adding a sub box is essential for getting accurate bass reproduction at high volumes. The shape of the cab in the Ram means a custom-designed and built sub box is the best way to go because the cab is a very different shape than most of the cars the sub boxes are designed for.
Measure the area behind the seats. This is the best place to mount the box, but the exact dimensions depends on whether you have a regular cab, an extended cab or a crew cab. Write down the dimensions on the paper.
Measure the sub and add 2 inches to the depth and diameter to get the minimum dimensions for your sub box.
Calculate the interior volume of the sub box by subtracting twice the width of the medium-density fibreboard (MDF) from each dimension and then multiplying the length by the width by the height. If you were using the recommended 1/2-inch MDF, you would subtract 1 inch from each dimension (2 times 1/2) before multiplying the dimensions together.
Read the documentation for the subwoofer to find out the manufacturer's recommended enclosure size. It should be listed on the documentation that came with the sub. Compare this volume to the volume of the sub box you have built and adjust the dimensions until you have a box that will fit within the space your measured in the truck and meet the recommended specifications for the subwoofer.
Cut the sides out of the MDF with the jigsaw. Cut out two pieces for the front so that they can be connected together and add strength. Draw the outline of the sub on the front pieces. Drill through the material you're going to remove, and then use the hole to put the jigsaw through and cut out the rest of the material.
Use the same method to make a hole in the back for the terminal cup. The terminal cup is a connector which has two terminals that can be permanently wired to the speaker on the inside, but can be easily connected and disconnected on the outside.
Assemble the box using the screws and wood glue to hold the sides together. Screw the long sides into the short sides. This gives the box more strength.
Caulk the inside of the box with the silicon caulk. This seals the box and gives it strength.
Put the terminal cup in place and secure it with screws. Attach the speaker wire to the inside terminals of the terminal cup. Run the speaker wire through the box and attach them to the sub. Put the sub in place and secure it with screws.
Attach the heavy-duty Velcro or similar adhesive to the underside of the box with the wood glue, and attach corresponding pieces to the carpet of the truck with fabric glue.
Run speaker wire from the amplifier in the truck to the position you are mounting the sub. You can lift the edge of the carpet and the trim with the screwdriver and hide the wire underneath.
Attach the wire to the terminal cup on the back of the speaker and put the speaker in place on the Velcro.
