upgrade my sound!!


I need some advice. I currently have a basement home theater system with Paradigm signature S series fronts and center channel. The rears are also Paradigm installed in ceiling. My sub is a single 212/SE. Its great, but I was considering whether I should replace it with two S/812s for more balance and sound. I would also be replacing the Paradigm signatures with newer Persona models, if that is relevant. My processor is a Marantz AV 8805. the power amp is a Audio Control Pantages G3.Thoughts? 
mcgintyman
Add 2 subs. Three will give you incredible smooth, tight, articulate and deep bass like you won't believe. Do not sell one, add two. Put each one a different distance from a corner.

Right now with one sub there are areas where the bass waves cancel creating a dip or drop-off. So you turn it up and this is what creates the boom. Running more subs in different locations moves these areas around until the overall response winds up being very smooth and even. Smooth bass is fast accurate bass. It will also go a lot deeper. Incredible improvement.  
Yeah I’ve been intrigued enough about the 2 sub discussion to try it.  When I first got into the hobby about 20 years ago the conventional wisdom was that was unnecessary but it seems like everyone is recommending it now.  I won’t do it in two channel as I wouldn’t have the room and I’m very happy with that system now
The most effective, easiest and actually cheapest solution is four subs. The number of subs is far more important than how big or powerful or any of that. So no it is far from everyone is recommending it. Most are still stuck in the old school EQ one sub approach. A few now are starting to realize more is better. But then they get stuck in the rut of thinking stereo. Low bass is not stereo. Timing, etc, none of the usual stuff applies. Just get four, you will not believe. The last guy to do this PM'd me with, and I quote, "F---n f--k this is awesome!" Just do it. 
I see the logic.  4 subs, one for each corner of the room.  Right now, that might be a bridge to far for me.  I’ll start with 2 and see how it goes.  Do you recommend all subs be of the same manufacturer?