How To Meausre Port Length For Rear Deck Blow Through

[Texas Tech]

How would you measure the port length you need to know for the tuning of your enclosure when the port is inside the enclosure, but extends outside the box and proceeds to the rear deck to blow through... An example of a port of what I am trying to figure out how to measure would be in here, Post #11.

http://www.stevemeadedesigns.com/board/ind...showtopic=37362

In this simple paint diagram I made, the bold, thick, black line is the rear deck. The port starts inside the box and proceeds outside the box until it meets the rear deck, where it would blow through the rear deck (like the build i the link above, shown in post #11).

Would the way you measure this be the physical port length of 27"+the end correction of the port on the inside of the box?

[bobonit]

The length of the port does not change whether it is inside or outside of the enclosure. What changes is the displacement of the port. If the port is inside the enclosure you need to calculate the displacement so you do not include that in the enclosure volume. If the port is outside the enclosure, you do not need to worry about port displacement as it does not take up any space inside the enclosure. Now, in your situation you need to figure out the displacement for the section of port that IS inside your enclosure.