4yanx...The integral subwoofer that you describe in the Vandersteens is a very good approach. What you end up with is a four-way system. A passive crossover for a three way system is a tough design job, and a four way would be worse, hence the use of the electronic crossover and separate power amp. Also the inductor and capacitor values that would be needed for a passive SW crossover are large and expensive. Last, but not least, the all-in-one aspect has definite cosmetic benefits.
The only drawback that comes to mind is that the SW enclosure size is probably less than what you could use for a separate SW. When I built a tower system with integral powered SW I used the "isobaric" design (two drivers mounted one behind the other in a short tunnel) so as to cut the enclosure volume requirement in half.
The only drawback that comes to mind is that the SW enclosure size is probably less than what you could use for a separate SW. When I built a tower system with integral powered SW I used the "isobaric" design (two drivers mounted one behind the other in a short tunnel) so as to cut the enclosure volume requirement in half.