How to Build a Plexiglass Subwoofer Enclosureby Jose Leiva ; Updated September 28, 2017
Items you will need
2 plexiglass sheets: 13.5-inch by 13.5-inch by ¼-inch
4 plexiglass sheets: 13.5-inch by 9.5-inch by ¼-inch
Building a plexiglass subwoofer enclosure is not much different than building a subwoofer box out of any other material. In subwoofer enclosures, the wooden box with an upholstered exterior is only done in order to have the enclosure blend in with the interior of a car’s trunk. These things are not necessary, however, and a functioning subwoofer enclosure can be made with plexiglass.
Figure out how much air space your subwoofer needs. For example, a P3 style subwoofer requires 1 cubic foot of airspace, so your box must enclose at least 1 cubic foot.
Figure out how tall and how wide you want to make the box. These dimensions will depend on where you plan on putting your subwoofer.
Figure out how deep the box needs to be to enclose 1 cubic foot. To do this take one cubic foot (1728 cubic inches) and divide it by the height, then divide it by the width--this will give you the depth of the box. So if you are building a box that is 13.5-inches wide and 13.5-inches tall, then you need to make the box 9.5-inches deep.
Purchase plexiglass sheets that match the dimensions of the box you will build. In this case you’ll need two 13.5-inch by 13.5-inch squares and four 13.5-inch by 9.5-inch rectangle pieces. The plexiglass should be no more than ¼-inch thick.
Cut a circle at the center of one of the 13.5-inch by 13.5-inch plexiglass sheets that matches the circumference of your subwoofer. To make the circle, draw the circle with a compass, drill a hole into the center of the circle, and then cut out the circle with a jigsaw.
Build a frame using the four 13.5-inch by 9.5-inch plexiglass sheets. To attach the pieces, apply acrylic cement to the corners of the frame. The acrylic cement will melt and glue the sheets together. Allow four hours to pass for the cement to dry before continuing.
Close the frame up with the two 13.5-inch by 13.5-inch plexiglass sheets. Attach the sheets to the frame using the acrylic cement and allow four hours to pass for the cement to dry.