Most efficient enclosure type

[0kriz]

Technically speaking, what subwoofer enclosure type would you guys concider to be the most efficient?

By efficient im thinking spl/size ratio in open field environment. 

 

 

Conditions for the discussion:

   - Any driver available in the market can be used

   - It is unlimited power available to power the subwoofer.

   - Frequency range should be below 100hz and atleast 1 octave wide

 

 

My hypothesis is that it  depents on the size of the enclosure.

If an enclosure is to small, a 6th order bandpass would for example not perform as well as a bassreflex due to the ports being to small to move any significant amount of air. 

When it comes to what enclosure type is the most efficient I personaly dont know.

 

What do you guys think is the most efficient enclosure design?

Do you think the size of the enclosure will affect what enclosure type is the most efficient ?