Ported Enclosure
A bass-reflex box with a tuned port — more output per dollar, best in larger rooms.
A ported (bass-reflex) sub uses a tuned port to reinforce output near the tuning frequency, buying several dB of extra SPL per dollar. Below tuning it rolls off steeply (~24dB/octave). In large rooms where room gain is weak, that output economy wins; in small rooms the same alignment can boom. Room size picks the winner — see sealed vs ported.
Category: Subwoofers