The use of an electrical resonant circuit between the amp and speaker allows greater bass extension from overdamped alignments, closed or vented. However, for vented designs, this does not offer the benefits of cone motion damping/reduction near Fb: increased power handling and reduction in excursion related distortion.

I wonder if there may not also be a potential problem with amplifier stability due to the reactive loading produced by the resonant circuit.

Best,

Bob