I generally agree with
@wattsperchannel I also very much agree that integration is much more important than getting the most massive or beautiful or well reviewed sub. Very good very powerful and capable subs are available relatively inexpensively. You may find a lot of information on that here:
http://www.data-bass.com/homeHowever.... proper bass traps and EQ get you very close to ideal, so much that you may not want the second sub. Buying 1 sub does not stop you from buying 30 more later. Subs are not rationed per family. :) and it’s your wallet, so buy as many as you’d like. I only mean to let you know what the cost/benefits are, and that there are diminishing returns after 1 "well integrated" sub.
Lastly, I keep saying "well integrated" because subs are a nightmare for some one who does not do this professionally, or build loudspeakers, to integrate well. Whatever you do, do not expect to drop it down and have it work. It takes time, measurement, and accessories such as appropriate room treatment and adjustment for EQ, crossover, delay, phase not to mention it takes muscle to locate the sub in the ideal place. More so with 2. When I set up a sub I don’t approach it as a sub but as part of the speaker.
I’m very happy with a Hsu VTS 15, and a miniDSP unit + GIK acoustics soffit traps, but I have a background in crossover design and audio that makes this relatively easy. A sub with a push button EQ may do much for you. If you go that route then I _DO_ encourage you to ask owners. Auto EQ systems are quite variable in quality. You’ll want to hear owners experiences.
Another good source of help is the Room EQ Wizard forums. There are many people there who will help you with measurement, interpreting and setting up subs.
Best,
Erik