Wayne Parham Messages: 18748 Registered: January 2001
Illuminati (33rd Degree)
I generally recommend that R-13 be installed on the back, bottom and one side. Unless the cabinet is very small, I would not trim the insulation to make it thinner, except do remove the vapor barrier, if present. Position of absorbent material is important and its spacing from the boudary in particular. An absorbant material is most effective when placed at least 1/4 wavelength away from the boundary, and this must be balanced with the issue of viscocity change from having a lot of damping material in the cabinet.