Port Length?

Question

Okay so I have a speaker box that is (external)16.5" h x 18" w x 20" d and it has an air space of 2.864 ft^3 and a vented port of (internal) 2" h x 16.5 w x 18.75" d.

How would I measure the displacement for the port? Or would I even need to measure any displacement for the port since it is using the wall of the box. What would the box be tuned to? (Is it around 40hz?) Also what size would I need to make the port if I wanted it to be tuned to 33hz.

Your help is greatly appreciate. Thank you very much.

Answer 1

How would I measure the displacement for the port?

I am assuming you are using .5 inch thickness for your box.

(17 * 19) - (16.5 * 18.75) = 13.65 square inches

this equates to a port diameter of 4.168 inches

box volume is 2.864 cubic feet

this puts your tunning at 27.73 hertz

tunning to 33 hertz you need to go from 13.65 square inches to 8.75 square inches.

Hope this helps.

email me if you need more help...

: )