Wayne Parham Messages: 18835 Registered: January 2001
Illuminati (33rd Degree)
MDF is wonderful material for these speakers. Since the port length of the two π tower is set by its rear panel thickness, the Helmholtz frequency is a function of the thickness of the wood. Here are some recommended hole sizes for various panel thicknesses:
1" thick panel => 4-3/4" diameter port cutout
3/4" panel thickness => 4-5/8" diameter port cutout
5/8" panel thickness => 4-1/2" diameter port cutout.