JB, welcome. The difficulty in answering your question with any degree of precision is that the mixture of various speakers that you now use are unfamiliar to us as a complete setup. Whether you go with Axiom, Polk or other speakers, you should match them to the extent that your budget allows.
If you get quality main speakers and a good sub, you won't "lose bass" in a real sense. Bigger woofers in some older speakers provide a bloated, boomy(superficially impressive to some)bass which is inaccurate when compared with some smaller woofers which give you a more honest picture of the program material.
