bear with me.. iam an idiot lol

so still new to the whole box fabrication deal... so if a driver calls for two 4" port and making a dual box. that would be 4 4" ports. now to change that to a slot port do I add all of that area together eg.(Pi x r(squared) by 4)

also have a minimum port size formula. this look correct?

dv>39.37*(Fb*vd)^0.5

dv=required diam of port
Fb=tuning freq
vd=X-Max in meters * sd

and for port length
Lv=[1.463x10^7*R^2 / Fb^2*vb]-1.463R
where
Lv=port length
Fb=tunning freq
vb=volume in inches
R=radius

for multiple ports devide enclosure volume by the number of ports. then use that as vb.

for a square port
R= sqrt of a/Pi
where a is the area of square port. is this the formula you would use for a slotted port? or is a slotted port different? I know it would be a rectangle rather than square but would this give the same area? rather than 8x8 square port would a 16x4 be the same?

these formulas look good?
(ranger, azn?)

 

oh i waqs just wondering, those are the Formulas i use from the cookbook, just wondering if anyone else used different formulas, any input at any time is fine