Vandersteen Sub woofers v Rythmik Subs


I really love the idea of the Vandersteen Subs where they are connected with the mains via extra speaker cable off right and left channels off the main amplifier, which is supposed to provide better bass transition from the mains while keeping the signature from the main amplifier. My question is with Vandersteen coming out with the SUB THREE and the price going significantly higher, I was wondering if there are other subs for less that you could integrate in the same way. (Most subs seem to rely on the line level input which is just a sub-woofer RCA going from the pre-amp to the amp on the sub). Can this same Vandersteen set-up be achieved with other subs?
I picked Rythmik since they are known (in the home theater community anyway) for being one of the best bang for the buck subs and the most "musical" of the bunch. (between Hsu, SVS, PSA).
And could I possibly achieve even greater sub-woofer nirvana since I could get an 18" for around $1500? Vandies only have 3 eight inchers.

I am a Vandersteen fanboy and I would like to support RV whenever I can, but don’t know much about my other sub-woofer options so looking for some feedback. Doesn’t even have to be related to Rythmik necessarily. If you know of other subs that can integrate the same way I want to know about it!

Thanks
bstatmeister
Hola Horacio,

     So, your 'cheers' sign-off does indicate your British heritage but you're now living in Argentina, interesting.
     Yes, I share your interest in room acoustics, have read many white papers from leading acoustic scientists' research and read a lot of various online audio blogs on the subject.  I've learned quite a bit but definitely do not consider myself an expert.
     My main focus has been an attempt to attain the best sound reproduction for 2-ch music and ht in my 23 x 16 foot living room.  I've basically been trying to adapt what I've learned to my room and system. 
     For example, one of the principles I learned was that it's more difficult to attain good bass response in a given room than good mid-range and treble response
.  Therefore, I decided to initially concentrate on attaining very good bass response in my room as my goal.
     The findings of acoustic engineers Earl Geddes and Floyd O'Toole were instrumental in my decision to employ a distributed bass array system to attain state of the art bass performance.  It has been scientifically proven, by Geddes and O'toole and independently verified by others, that bass standing waves are reduced (and bass response improved) in any given room as more subs are added.   
     They also found that bass standing waves will be significantly reduced as subs 2-4 are added and that the vast majority of standing waves are eliminated by deploying 4 subs; any subs added beyond 4 will only result in relatively smaller improvements.
     Because of the above,I decided to purchase and install the Audio Kinesis Debra distributed bass array system that consists of four 1' x1' x28"  44lb. 4 ohm subs with 10" drivers all powered by a 1K watt class AB amp.  
     This system has allowed me to reach my goal of very good bass response in my room as a solid foundation for my system to be built upon.  It not only provided accurate, smooth, textured and effortless bass at my listening position but also at the 5 other seating positions in my room. I believe it's possible to achieve this level of bass response utilizing as few as 2 subs if properly positioned but the bass will only be optimized at a single 'sweet spot' seating position, not throughout the entire room. 
     Once the bass system was installed and functioning at a high level, I found I only needed to independently dial in the mid-range, treble and sound stage imaging and illusion at my listening position.  I have large Magnepan 2.7qr panel speakers and this was relatively easy to do by experimentation with their positioning; distance between the left and right speakers, distance from my listening seat, distance out from the front wall,angling or toe-in and room treatments at the first reflection points.  
     I've come to the conclusion that it's best to treat any sound system as 2 systems: a bass system and a mid-range/treble sound stage imaging system.  I've arrived at this conclusion by research but also by applying this research in my own room and system(s).

Hope this helped a bit,
 Cheers,
Tim 
Funny as I've been ready to get the Audioquest power cables, but am thinking I really need to get my acoustics down first.  That will make a larger upgrade in sound than even great power cords regardless of how great they are (they too are a component upgrade).  
Speaking of Vandersteen Sub woofers, looks like they got the page up for the SUB NINE. Holy smokes that looks like a beast! Check out that last pic next to the model 7s

http://vandersteen.com/products/sub-nine
It's really interesting with the first sub I ever owned being the Vandersteen 2Wq. I am using it with a pair of Treo Ct's. Bought the HP-5 crossovers, new. I put the lone sub in the right corner, adjusted the crossover frequency, and output of the sub. That was all there was to it! Sounded great from the get go. I used a recording of a jazz standup bass and adjusted output so upper bass frequencies were same volume as lower bass frequencies, as RV suggested. Tried bringing out the sub from the corner, but corner placement in my room sounded best. Near perfect balance of frequencies across the board. Even when a stand up bass is located left in the soundstage, the speakers make the sound come from that position perfectly even though the sub is in the right corner. The front main speakers maintain a stable image from left to right. What more could I ask for???