A subwoofer is like salt. You should only notice it when it is missing. If you can "taste" the sub, then you have too much. If you're used to over-the-top, bloated, flabby bass, then the musical, subdued Axiom subs may seem lacking. Try turning it off when you're playing some music. You'll hear it go away; even if you didn't think it was there to start.
I like to play "name that bass line". Take a boomy sub and turn off the rest of the speakers. Have someone play a track and see if you can identify the song only by the <80 Hz component. With a good, musical sub this usually isn't a problem. But with a one-note boomer, if you can't pick out the song by the rhythm, you're stuck because there's no melody.
