Subwoofer recommendation for swarm


I want to create my own subwoofer swarm am looking for reasonably priced units, want to stay under 2K.  Recommendations welcome.  My room is 20' L X 13.5' W X 9' H. 
zardozmike
Qty 4 SVS SB12 NSD for only $1600 might be the best deal out there for complete, already built with amps, etc...and they measure extremely well.
I`ve been using the Dayton SA 1000 subwoofer amp for a few years now powering a Revel sub.
The sub has a 15" woofer in it. I`d like to do a swarm but still use the Revel.
Is that feasable ?

Sure is. I'm using 2 Daytons to drive 4 Morel 10" subs. Two ported, two sealed. Plus one Talon Roc powered sub. There is absolutely no problem mixing sub brands, drivers, enclosures, amps. You can add subs and drive them with the Dayton, or add powered subs, either way. Just whatever subs are used be sure to know their impedance and know how to connect them in series or parallel to yield the total impedance you want and your amp can handle. If you do run multiple subs I suggest comparing the different loads. Most prefer the tighter more articulate bass of higher impedance (16 ohm) than low (4 ohm) which while it yields a big more power tends to sound a little tubby compared to 16.

While my setup uses two the same four can be run with just one Dayton just fine. While low bass with a DBA is impressively 3D and seamless with the rest of the sound stage, this bass imaging localization is all coming from mid bass on up. All subs can be run mono and nothing whatsoever is lost. Finally, don't waste money on sub speaker cables. Duke himself tipped me off to this and while this was hard to believe its true- which I guess being Duke almost goes without saying.
Thanks millercarbon ! I`ll need to do my homework.

I think I read somewhere that sending a signal to a powered sub via speaker level adds no strain or something like that to the amp ?

The big Revel sub could keep using the Dayton amp then I could add other powered subs to the mix.
So really after digging around, it seems that the swarm method could be accomplished with 4 less expensive subs like the kit ones from Dayton Audio or built ones the Klipsch`s , Polks etc..

Providing they have speaker level inputs and are powered ? 
Why is speaker level inputs a requirement? Can I just split the LFE signal from the receiver into 4?