Can any sub be put in a ported box

[screamerbolt 10+ year member]

The reason I am asking is because I was looking through the manual that came with my subs and it has a "recommended box size" section.It gives the box size for a sealed box but next to it says"ported box size- N/A. actually it has this:sealed box-2.5cu.ft ported box-N/A F3 freq.34hz. What the hell does that mean?The subs are o2 OW-15's

Click to read more...

 

[JimJ 5,000+ posts]

Quoted from the Loudspeaker Design Cookbook:

"Woofers intended for use in closed-box systems are characterised by low free-air resonance (fs), relatively high cone mass, and long voice coils.... In terms of driver Qts, closed-box loudspeakers generally require woofers with a fairly high Qts of greater than 0.3... R.Small suggested a good rule-of-thumb which he called Efficiency Bandwidth Product (EBP).

 

EBP is quantified by:

 

 

EBP = Resonance Frequency / Driver Electrical Q

 

or EBP = fs / Qes

 

EBP in the vicinity of 50 or less indicates a sealed enclosure would be more suitable, while EBPs of about 100 suggest a vented enclosure."

 

[GrnEydDvl 10+ year member]

It means based on their conclusions those subs will perform like *** in a ported box.

F3 is the 3db down point for the sealed enclosure in an anechoic chamber (ie no cabin gain helping out like in your car).