As I posted earlier, the problems with subs is that they can never properly mate with a speaker regardless of size if they can't have a full octave overlap. Many speaker designers, who truly understand how physics work have told me that. I'm NOT a tech guy and NO I personally don't understand it all, but I've recently heard TWO very well known designers or engineers for manufacturer's discuss this and both said the same thing. Personally, I've never ever heard a sat/sub set up that was coherent. There is always something missing and it really throws off my ability to enjoy the music. For TV it's fine, but for listening to music it throws the brain off if there isn't coherency. The type of sub you use is irrelevant if there isn't a full octave overlap. The brain picks up on what's missing and can't fill it in.
This is one reason why Vandersteen will never offer a bookshelf speaker. They have theater speakers but not a smaller one. Their 1B has the same footprint of a bookshelf and very few who are serious about listening will put a bookshelf speaker on a bookshelf. I realize that I'm in the minority, but if you get designers to tell the truth, they will say the same thing. Now if you don't care about music below 50hz then some of the smaller speakers will be fine and some will be great for you. You just need to learn to live without the foundation of most music. Many do and are very happy that way and it will save you a ton since bass in all components is the most expensive part of the build and very few will disagree with that statement I think. This is interesting thread. thanks and I hope I don't offend anyone as that's not my intent. Just enjoy the back and forth.