Which of the T/S Parameters show wat kind of box to use?

[flakko 5,000+ posts]

i remember something being posted like this not too long ago and there is a certain T/S spec of a sub that lets you know if the sub will work optimally sealed or ported. Which one is it?

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[JimJ 5,000+ posts]

Efficiency Bandwidth Product...

Fs/Qes

 

[flakko 5,000+ posts]

and, what are the numbers that determine?

 

[PowerNaudio 10+ year member]

EBP:

taking the driver free air resonance (Fs) and dividing it by the electrical Q (Qes). If the resulting number is around 50 or less, you are looking at a driver that is best suited to a sealed type box. If the EBP is between 50 and around 100 or more, the speaker will work best in a vented enclosure. Horn loaded designs will perform best with an EBP of 150 or even higher.

Sealed box (and sealed bandpass) woofers should have the following characteristics:

Qts => 0.40

Fs

Xmax => 4 mm

Vented or ported box (and ported bandpass) woofers should have the following characteristics:

Qts

Fs

Vas should be relatively low (less than 4 cubic feet unless enclosure size is not a factor).