"Hi Seng, Two corrections... First, as for actual low end production, a ContraBass will out woof a pair of HGS-18s at low frequencies without too much trouble. I wouldn't hesitate to say the perception of the ContraBass with most DVD soundtracks would be like that of 2-4 HGS-18s, but 4...
Great review!
I would love to see a shootout between this sub and the ContraBass subwoofer by servodrive. According to Mark Seaton, 1 contraBass ($2500 without the amp)is equal to 4 HGS 18's!
Now the question is, which one of these is better?
www.soundphysics.com/cb.html
Seng