How to get tunning, square ports

[andym85]

how i would figure it texas, by using my equation is that your effective length=physical + end correction. end correction = half of the port width...so your effective length=10+2....so 12" for your effective port length, even though it is only 10" long, it is effectively 12" because of the use of the box wall for a port wall, creating the need for end correction.

[Texas Tech]

thanks for the help, its amazing how all those different equations, some easer and some harder, can give you the same tuning frequency.

Here is a link to illustrate what i was trying to create with words earlier (not the same EXACT scenario, but the same idea)

http://www.subwoofertools.com/forum/ported...=&Vas=&Fs=&CE=0

The board that actually creates the port is 10.25 in. long, however the baffle (the red board) is "in front" of that teal board, so i figured you would add on .75 in.(because that is the width of the wood) to the teal.

The port width is 1.75 in. wide (so half that)

So i would do 10.25+.75+.875=11.875, but on the wedsite it says teh port length is actually 12 inches wrong. What did i do wrong to calculate the port length?

[andym85]

that is pretty close...11.875=11 7/8...so there is 1/8" of a difference, that aint gonna be noticable