Wayne Parham Messages: 18786 Registered: January 2001
Illuminati (33rd Degree)
You'd have to ask the author to know for sure, but I think his statement is essentially a generalization that sets a "scale." There are other limiting factors besides throat size to consider, such as throat shape, front chamber size and shape, phase plug shape (if used), diaphragm size, shape and material, compliance and motor strength.