View Full Version : port length question

04-17-2006, 11:39 PM
For those of you familiar with bass box pro and/or winisd, help me out here.

The box is 2 cuft tuned to 30hz (12" rlp), 4" precision port

When I do this calculation (Lv=((8466.4*r^2)/(Vb*Fb^2))-(1.463*r) I get a number like 15.89". Winisd gives 16.28" with end correction being .614 (is that right for 2 flared ends?) And Bass box Pro gives a length of 17.35".

Which of these is correct? Or is there some other part if it I am missing? It seems as though they should all be the same length if my numbers are identical, but they obviously are not.

Also, a precision port ordered from PE is 17" in length with adding the flares and not cutting anything, correct?


04-17-2006, 11:41 PM
I dont know which is correct, but you wont hear an audible difference between the two lengths...

04-17-2006, 11:42 PM
Your first one is correct, BBP and WinISD are a little off and they won't fix it.