How to Use Isolation Inside a Speaker Enclosure
- 1). Install braces. Measure the inside depth of your speaker cabinet with the tape measure then mark and cut a piece off your 2 by 8 inch board to this length with your miter saw. Set the fence of your table saw at 2 inches and rip the piece you just cut into 2-inch strips. Repeat this process with a second section of board to get six 2 by 2 inch strips. Put wood glue on both ends of each strip and stick them through the holes where your bass and midrange speakers will be mounted. Wedge them between the front and back inside surfaces of the enclosure near the edge of the holes where your speakers will go. Put four evenly spaced braces around your bass speaker hole and two braces on opposite sides of your midrange speaker hole.
- 2). Install a damping layer. If you make your enclosure out of MDF (Medium Density Fiberboard) use cement board for the damping layer. If you make your enclosure out of plywood, use hardboard for the damping layer. Use your table saw to cut the side damping layer pieces 1/4 inch smaller than the space between the front and back of your enclosure. Cut the front and back damping layer pieces 3/4 of an inch smaller than the space between the sides of the enclosure. The smaller size of the front and back pieces will allow them to fit between the side pieces. Use your jigsaw to cut holes in the front damping layer for your speakers (make sure they line up with the holes in your enclosure). Apply panel adhesive to one side of each damping layer section with your trowel and press them in place inside the cabinet.
- 3). Install a damping lining. Use your tape measure to get the inside dimensions of the top, bottom, sides and back of your enclosure. Lay out these dimensions on the Deflex polymer panels with the marker and cut the panels to size with your utility knife. Spread panel adhesive on the smooth side of the Deflex panels and press them in place inside the enclosure.
- 4). Install a damping filling. Put on your work gloves and dust mask to avoid irritation from the fiberglass fibers. Use your utility knife to cut off a section of the fiberglass insulation and peel off its white plastic backing. Stuff this section into the enclosure through a speaker hole. Repeat the process until your enclosure is about 50 percent full, being careful not to cover the port if you have a ported cabinet. Try to distribute the filling evenly throughout the enclosure.
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