Given there are hundreds and hundreds of speakers on the market, there are obviously a variety of opinions as to what is the best approach to speaker design.
The Vas parameter is used in determining the bass performance of the speaker. One can model a number of different box volumes and see a significant change in performance under 100 Hz but virtually no impact on the performance above. If you reread what I wrote above, it is this range above the bass where it is often difficult to control the back wave re-radiating through the driver cone material.
Of course, cone material can be selected that is better in this one area, but that cone material may represent a loss of performance in other areas. Almost all engineering efforts represent finding those compromises that result in the best balance in the opinion of the designer. And, as is routinely demonstrated on this forum, there a considerable range of variety in those opinions. ;-)
The Vas parameter is used in determining the bass performance of the speaker. One can model a number of different box volumes and see a significant change in performance under 100 Hz but virtually no impact on the performance above. If you reread what I wrote above, it is this range above the bass where it is often difficult to control the back wave re-radiating through the driver cone material.
Of course, cone material can be selected that is better in this one area, but that cone material may represent a loss of performance in other areas. Almost all engineering efforts represent finding those compromises that result in the best balance in the opinion of the designer. And, as is routinely demonstrated on this forum, there a considerable range of variety in those opinions. ;-)