@resveratrol3 note that any smaller sub no matter how good may not be a good match to some speakers and/or room. If speakers are fuller range and not high pass filtered you probably need a larger sub to properly fill in the missing lowest octave. Also the larger the room the larger any sub up to the task properly will probably need to be. A smaller sub running with more full range speakers to start will be a challenge if even possible to blend in properly without merely delivering a big bass bump in the frequency range already covered. That could result in fat muddy bass that also obscures detail in the midrange which is not a good thing.