Personally, I'd cross the RSX3 off the list because they don't reach low enough. You'd have to run the sub to a pretty high frequency, for a sub. Those are all respectable speakers to consider. If you really like the RB10, go for it.
But, to help cause some further second guessing...
A few questions -
1) What is your budget you are willing to spend? (Lot's of people are gonna suggest expanding your budget no matter what you put.)
2) What other speakers have you considered? There are lots of options out there.
3) Approximately what size room will these be used in? (area and/or volume)
The Klipsch speakers are nice. You will definitely need a sub with
any set of bookshelf speakers (IMHO). The
RB10 will probably offer the best sound of the three bookshelf speakers you've listed. There are many choices in the sub $300.00 speaker price range.
I don't know if you have a Fry's Electronics nearby, but these would be worth checking out. I have not heard these:
Polk RTi A1 black or cherry
They have a much greater
frequency response than the Klipsch
Polk TSi200 black or cherry
Same thing on the
frequency response.
If you run the sub too high you'll start hearing sounds being emitted from the sub that shouldn't be. You'll also start to distinguish where the sub is actually placed which is not good (again, IMHO).
The Polks look intriguing to me if I were looking for bookshelf speakers in the $300 range. Fry's runs specials every weekend/day. Check the back side of a newspaper section. It'll be on one of them.
Just to reiterate, I have not heard the Polk Audio speakers I mentioned above. I have heard the RB10 and thought it was OK to my ears. I would definitely have a sub with any of the listed speakers. Crossover would be at 90hz for the RB10 (on paper) and probably between 60-80hz for Polk. The lower the crossover, typically, the better. It all depends on how well your speakers reproduce the low tones, how you like the sound of your sub, and how much bass you want.
-pat
