Before deciding on a particular type of enclosure to use, you must first determine the amount of space you have available. This is a very important step to ensure you have the appropriate volume needed to provide proper performance of the subwoofer. For example, if you wish to build an enclosure for a 15" and you only have one cubic foot space available, it would be better to use a 10" because the volume is not large enough to allow the 15" to perform properly. The small enclosure would restrict the performance of the 15" not allowing it properly reproduce low frequencies.

Sealed Enclosure

Advantages
Easy to build, smaller enclosure size, lean tight sounding bass, better power handling vs. ported design and Linear low bass extension.

Disadvantage
Less efficient as compared to ported design.

Ported Enclosure



Advantages
More output at the tuning frequency as compared to the same woofer in a sealed enclosure, higher efficiency.

Disadvantage
Larger enclosure size, Calculating enclosure and port dimensions more difficult,easy to blow woofer if power handling limit is exceeded.