Sealed Enclosures

A sealed subwoofer houses its driver in an airtight enclosure, with no port: bass comes solely from the cone, which works against the sealed air volume inside the cabinet. This air spring limits cone excursion, giving this type of subwoofer its characteristic sound. Bass rolls off gradually, with a gentle slope rather than an abrupt cutoff, and above all it starts and stops quickly: the cone is better controlled, transients are clean, and bass remains tight and precise without lingering. Phase response is also better, helping the subwoofer blend with the main speakers. Music and hi-fi enthusiasts appreciate this control. The trade-off is physical. With the same enclosure volume and driver, a sealed subwoofer reaches less deeply and delivers less output than a bass-reflex ported model, which gains extension and impact at the cost of bass that can sometimes be less controlled. A sealed subwoofer therefore requires more amplifier power and a long-excursion driver to reach the lowest frequencies, which explains the robust cones and powerful amplifiers found in good models. In return, the cabinet often remains compact and is less sensitive to placement in the room. This choice prioritizes accurate bass over spectacular impact. This subwoofer belongs to the subwoofer category, connects to the amplifier via a subwoofer cable, and complements a pair of hi-fi speakers in the deep bass range.