Which subwoofer should I get?

Many subs can move lots of air. But integration tools (DSP PEQ) to tame room modes can make a less expensive air-mover sound magnitudes better than many very expensive air-mover that operates, more or less, open loop at the mercy of standing waves.

@misterbobman While DSP can certainly help a lot and is very convenient, proper room placement and carefully dialing in the sub’s controls can achieve the same thing or better in taming modes/nodes (DSP can’t do anything about nodes BTW) and achieving excellent results — just takes a little research and effort, and it’s not all that hard.

"...to tame room modes", not "nodes".  Please refer, with accuracy next time, to my entry.

FYI:  https://en.wikipedia.org/wiki/Room_modes

"...equalization is part of the necessary treatment of room modes in bass. There is no escape from that, but even there, something that should be simple is sometimes compromised."  Chapter 8 in the 3rd edition Toole, F. E. (2015). “The Measurement and Calibration of Sound Reproducing Systems”, J. Audio Eng. Soc., vol. 63, pp.512-541.

Well, I can’t believe it’s taken me this long, but I finally have my subwoofers! I purchased a pair of Rythmic E15HP2’s. Just starting to play with them. Will have some feedback and questions over the next few days, but wanted again to express my appreciation to this group for the help you offered many months ago! 

Congrats — I think you made an excellent choice!  Please let us know what you think once they’re dialed/broken in, but I’m sure you’re gonna be really happy. 

@ Soix - thanks a bunch. Yes, will definitely keep the group apprised and provide some details. I have initially set the crossover point to 80hz, will see if that works.