i saw this, & was disappointed that vmps was not included. my retail $699 vmps larger sub (a bit more $$$ for their options, which i highly recommend), are so much better than what i've heard at even four times the price... w/vmps you need your own outboard x-over & amplification, but this is an *advantage*, imo - much more flexible, & better electronics.
my present subwoofer set-up set me back ~$2400, & this included two optioned vmps larger subs, a deluxe version of the marchand xm-9 x-over, & two adcom gfa555 amps (one purchased new back in '84). i wouldn't trade it for a pair of top-line velodynes or rels...
ymmv, doug s.