Is this diagram wrong?

[zachzchw 5,000+ posts]

http://community.webshots.com/photo/118877623/118877979NDsHOC

Heres the cutsheet someone gave me for this box:

2-30" x 22.75" (top/bottom)

2-30"x 14.5" (front/back)

2-21.5" x 14.5" (sides)

I think the port may be wrong. It says 4" wide, by 14.5" high, and 23" long. Is that right? The two cuts I have listed for the port are:

16.5" x 14.5"

14.5" x 2.75"

the diagram shows the port being 16.5" long, but says 23". Which is correct?

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[c_bednar]

This diagram is correct... there are two things that you have to take into consideration here... 1. is the thickness of the stock being used... the measured dimension of the port is 16.5 on the longest side, but is effectively 17.25". Also, the port bends, so you have to take into account the measurement of the opposite side of the port, plus the bend and then average them... when you do this, you end up with an effective port length of 23" +/- a few fractions of an inch. That 2" bend is also effective port area, so don't forget to include it...