Wayne Parham Messages: 18791 Registered: January 2001
Illuminati (33rd Degree)
The cabinet is just a hollow box but you will want to line it with R13 insulation on the side, the front and the top inside surfaces. You'll also want to put braces between panels that preload them and tie them together. Put a cross-brace just below the woofer and another about a foot from the bottom of the cabinet, and span the cross-section with a sheet of insulation.