The Sealed Box Subwoofer Enclosure is the easiest to design and build, and provides the most accurate bass and a linear response curve. Translation: High end sound quality. There's a price, though - sealed boxes are not as efficient as ported boxes. Let's consider:


  • Sound quality is best because box helps amp control speaker cone accurately
  • Predictable, smooth response curve lacking any "hot spots" that ruin listening experience
  • Typically sealed sub enclosures require a smaller box size than a ported design
  • Construction and design are simple and straightforward


  • Response is diminished by 3db or more over a ported box design
  • Cannot be tuned to optimize driver response as in a ported design

The sealed subwoofer enclosure design is best suited to classical, rock, country, and other types of music where extreme low end performance is not as important as snappy, tight pounding bass. It is also ideal in situations where the best sound quality is desired.

Because the sealed sub box design dampens speaker excursion, it allows you to use an amplifier output near the maximum rated power input of your subwoofer. Since it does not rely on moving a specific mass of air for optimal performance, a sealed subwoofer enclosure generally can be smaller than a ported enclosure. For a given subwoofer, the optimum box size for a sealed enclosure is typically 2/3rds the vlume of a ported box.

Use a sealed box subwoofer design in systems with ample amplifier power for the subwoofer, where space or sound quality are of primary concern, or when ease of construction is desired.

Typical Sealed Enclosure Volumes for Common Subwoofer Sizes

6.5-inch Subwoofer Driver
ranges from .1 cu ft - .6 cu ft

8-inch Subwoofer Driver
ranges from .2 cu ft - 1.0 cu ft

10-inch Subwoofer Driver
ranges from .2 cu ft - 1.75 cu ft

12-inch Subwoofer Driver
ranges from .5 cu ft - 3.0 cu ft

15-inch Subwoofer Driver
ranges from 1.5 cu ft - 6 cu ft