Need Help With Port Length

[EraOfDiscovery]

Well, here I am again up at 1 AM, this time on Christmas, about to lose my mind trying to design a box for my (2) SA-18's. I've got all the measurements entered into Torres (will list below) and have got the cubic footage and tuning I want, now my problem is trying to design this box on Google SketchUp, i know the port length is the measure down the center of the port and the physical port length is the measure of the actual wood used, but i can seem to transfer these numbers over too my design without it making me want to blow my head off. If I use the physical port length, the actual port length isn't right. If I use the actual port length, the port doesn't bend like it says it should. I don't know what measurements to use. If someone could just toss this box together on Google SketchUp and post a screenshot with the measurements shown, that would be SO helpful. Thanks, and Happy Holidays. -EraOfDiscovery

(All wood is 3/4")

Outer Dimensions

Box Height 27.75"

Box Width 48"

Box Depth 27.75"

Gross Volume 18.54 ft3

Net Volume 13.48 ft3

Port Height 26.25"

Port Width 8"

Port Length 25"

Physical Port Length 16.25"

Port Bends Yes

Port Area 210 in2

Tuning Frequency 32hz

Common Walls 3

[OrionStang]

If you want to keep your 8" wide port, just make your physical port piece 17.75". Makes for a bit lower, 31.5hz, tuning, but makes it easy.

You have the double baffle- 1.5"

Physical port piece - 17.75"

90 degree of the port - 8"

Port piece thickness - .75"

Id go with a little less port width, but what's above will work.