Editorial Note about Sealed vs Acoustic Suspension Enclosure by James Larson:
As excursion for bass drivers have grown larger, high compliance suspension of the type needed for acoustic suspension design becomes more difficult to engineer for reliable performance. The thin suspension components needed for high compliance suspension are susceptible to self-destruction at high excursions, not to mention increased distortion from rocking modes and deformation. Furthermore, air doesn't have enough damping force against the effects of progressive suspension for high excursions. At high excursions, the suspension must be able to damp itself, and that means that it has to have lower compliance than an acoustic suspension system would call for. Acoustic suspension was a more viable solution in older eras of loudspeaker design when one-way linear excursion could be around 5mm, but modern designs aim for much larger excursions where high compliance suspensions become impractical.
