What determines the best type of enclosure for a paticular woofer (sealed, venterd, single-reflex or dual-reflex bandpass enclosures)?

Generally speaking, there are some speaker specifications that lend a driver to one type of enclosure over another, although most drivers are suited to more than one type of enclosure. ***These are generalizations and are NOT cast in stone!***

Woofers that perform best in sealed enclosures (or single-reflex bandpass) usually have a lower Fs, slightly higher Qts and more Xmax than woofers designed for vented (or dual-reflex bandpass) enclosures.

There is also a formula to calculate what is called the "efficiency bandwidth product" of a particular driver. The EBP of a woofer can be used as a guideline for the enclosure type. It is calculated with the formula:

EBP= Fs / Qes

EBP in the vicinity of 50 or lower indicates a sealed enclosure, while EBP of 100 or higher indicates a vented enclosure.

***Again, these are suggestions only, as the equations simply show a woofer's "preference". The best enclosure for you is the one you like the sound of best!***