2 medium sub or 1 big sub???

[Geoffcin]

I have a paradigm PDR-12 (150W RMS / 450 Peak) and it was "assisted" w/ a no name 60W RMS sub... now I have sold this sub which was part of a "surround package" and it doesn't sound as good with only one sub

My question is... should I buy a second PDR-12 or PS-1000 (200RMS / 750Peak) or sell my PDR and only get one PW-2200 (400W RMS/1500Peak) ????

Then adding another one makes sense. Your going to get sticker shock when you see how much a PW-2200 costs compared to the PDR, and your really not going to get that much more bass from it. It will go slightly lower than your PDR-12, but louder...not by much.
The extra coverage you get from dual subs is something that you've grown used to, and are missing. In my opinion one sub, no matter how big it is, isn't going to give you what your looking for.