Wayne Parham Messages: 18728 Registered: January 2001
Illuminati (33rd Degree)
Excursion is limited the most in the region between Fo and Fh, so I suppose you could say that's where the cabinet is assisting to control the woofer the most. Fl is the frequency where port output is highest, so you can view Fl to Fo as the region where the box is helping to augment falling output from the woofer. So you can see that the entire range of Fl to Fh is significant in bass-reflex tuning.