4th Order Bandpass. 8" woofer

[deez283 10+ year member]

It varies based on the sub. Really it depends on xmax and piston area.

Low xmax subs don't need as much port area, same for smaller diameter subs.

It pretty much is the result of the total volume the sub can displace being shoved through the port. The smaller the port the higher the port air velocity. At certain points it turns into noise.

Too much port area results in a narrow bandwidth before the port unloads. That narrow bandwidth can result in excellent efficiency inside that bandwidth. Think burp box.

15in² is what I try and use for regular 15-25mm x-max subs. Aeros I run 7-10 usually to save space

Now what about doubling subs, should the port area be doubled when subs are?

 

[winkychevelle 10+ year member]

Now what about doubling subs, should the port area be doubled when subs are?

Pretty much yea.