Your JBL might well have a hump in the 80-200Hz region that may provide a subjective impression of a "punchy" bass depending on personal preferences (I know many JBL speakers do this). The Axioms don't -- the M80's bass is highly accurate, tight, and "fast," which you may feel anemic at first. That said, the M80s may somewhat lack the energy in the very bottom octave (20-40Hz) depending on the room placement (I doubt that the JBLs have a real, clean energy in this region, either). A good sub will certainly help in the bottom octave.
