Determine the Space Available for Your Enclosure

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.

Enclosure Types

Sealed Enclosure:

Advantage: 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 (Bass Reflex):

Advantage: 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.

Bandpass Enclosure (4th Order):

Advantage: Bandpass can be designed to play loud or low depending on your needs, by design produce a limited band with, the woofer cone does not move as much as other designs reducing the chance of added distortion.

Disadvantage: Bandpass boxes have a tendency to sound boomy not tight, typically these enclosures don't sound as good reproducing music requiring great detail such as jazz or classical music.