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

So I did look at some of the Rythmic models on their website, and appears that the speaker level inputs are standard speaker level inputs.  This is completely different than the Vandy design.  The plate amp on the Vandy sub has a very high resistance rating, so it draws no power from the amp.  But the Vandy sub amp has a built in first order roll up beginning at 80 Hz.  The crossover you insert between the preamp and the main amp has a corresponding roll off, first order.  So, while you could set up a Rythmic sub to mimic this feature, you are not connecting the mains and the speaker level inputs to the same main amp tap like with the Vandy sub.  IMHO, that's where the magic happens.

I have heard of the rythmic method before. Maybe it was in one of @tubebuffer  posts?

I have an older Vandy 2<something> subwoofer, and it seems to work fine.

Hi,  I have owned two Vandy 2wq subs for almost 10 years, they integrate very well with my Gradfent Revolution mains (passive version). About a year ago i read about the swarm DBA system and decided to add two passive  10 inch B&W sw10 subs with the Dayton 1000w amp that is used for the swarm system.  It works okey having the Vandy subs in the front and the passives on the back, but really the Vandy subs make about 90 % of the spl of lows in the system the system, I don,t know if those B&W subs are not adequate ( I think they are more marketed for HT instalations and are not very efficient nor musical), those are 4 ohms and I,m connecting them in series to make the load 8 ohms. Do any of you can recommend  to upgrade those back passive subs, preferably with  some DIY solution where i could buy just the drivers and make the enclosures locally. i,m located in Mexico and ordering a couple of  Audio kinesis subs would be very expensive to ship down here.  I have a gut feeling that those B&W subs can be substitued for something better and that this idea of combining both aproaches can work. What do you think?

I think Rhythmic might have a flat pack kit cabinet, that would be fairly economical to ship. You might first try putting more input to the B&W subs, for a swarm to work you need fairly consistent output from subs in different places in the room to cancel out dominant modes.

Jim