The space station technology is patented so it's unlikely that there will be anything similar to this coming out anytime soon .
And a sub is not absolutely necessary. It's really only needed if you want to play in a balls out full rock band at ear bleed levels . 99 percent of the work I do will never need that kind of muscle (thank God ). And if you ever need that any basic sub will do .
a) the space station technollogy is very similar to what bose does, very similar, and the idea behind it is exactly the same..
b) I think a subwoofer is more about getting those very very low bass sounds then it is about the volume of the bass notes..