Gear & technology
Sealed enclosure
Also called acoustic suspension, closed box, sealed speaker
A sealed enclosure is a speaker cabinet with no port, so the trapped air acts as a spring behind the driver. It gives tighter, more gradual bass than a ported box and sits happily near walls, but produces less deep bass for its size.
Because the roll-off below the cabinet’s limit is gentle, sealed speakers often sound more extended in a room than their specifications suggest, and they take equalization and Subwoofer integration well. Owners describe the bass as tight or dry compared with a Bass reflex design.
The trade-off is efficiency. To reach the same depth as a ported speaker, a sealed one needs a larger box, a longer-throw driver or more amplifier power. Many sealed subwoofers rely on hundreds of watts of Class D amplification for exactly that reason.