Sealed vs ported, and how low is low enough
A subwoofer’s job is the bass you feel. The enclosure type and its low-frequency reach shape whether that bass is tight, deep, or both.
Sealed is tight; ported goes deeper
Sealed subwoofers roll off gently and tend to sound tight and accurate — great for music and mixed use. Ported designs use a tuned vent to reach lower and play louder for the same amp power, which pays off for movie bass, at some cost in outright tightness.
What the frequency number means
A sub rated “down to 20 Hz” reproduces the deep rumble in film soundtracks; one that stops at 30 Hz covers most music and casual movies but misses the lowest effects. Deeper extension needs a bigger box and more power, so match the spec to what you actually watch.
Two smaller subs beat one big one
If deep, even bass matters, two modest subs placed apart smooth out the room’s peaks and nulls far better than a single large one. It is the highest-value upgrade most rooms can make.