Wayne Parham Messages: 18786 Registered: January 2001
Illuminati (33rd Degree)
Several models use a rectangular port; Some cylinder diameters are hard to obtain so I use a box-shaped port instead. And as long as the port isn't too small and power very high, port sound isn't a problem. But if the port is too small and airspeed becomes too high, you'll hear 'em chuff.