Wayne,I am planning to make my Four-Pi modular by putting the 2226 woofer in a 3.0 cu ft Parts Express subwoofer cabinet. If I put 4 x 1.375-in ports in the corners of the front face, WinISD says each port should be 2.91-in long for 40 Hz tuning. Does this square with what you would calculate?
Craig Vogel