Lv (effective length) - Box Tuning

[dleccord 5,000+ posts]

decided to learn how to tune so i am looking at the Fb formula on JL's site. i got most of the terms down except for the last part of the Lv(eff) . is this some kind of barrier between the port and the backwall sorta? not sure if i'm suppose to plug Lv(eff) into the formula. but i am suppose to plug Lv(phys) in it right?

http://mobile.jlaudio.com/support_pages.php?page_id=165

what does C represent? thanks!

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[Volenti 10+ year member]

C represents a virtual extension of the port because one wall of the port continues to extend past the end of the port, you use Lv(eff) in calculations.

 

[squeak9798 5,000+ posts]

If you are using one of the walls of the enclosure as a wall of the port aswell then you would want to use Lv(eff). C is for what is commonly called the "port end correction factor", because as Volenti mentioned one of the walls of the port extends beyond the port and this creates a slightly longer "effective" port length.

 

[PV Audio 5,000+ posts]

Holy shit... YESS! Squeak is back.