I'm in the midst of constructing the pro pi7's and have a question concerning the port. Is the 15 1/8" dimension on the plans the distance from the outside of the cabinet to the partition that defines the length of the port?

Also, I was going through the pialign program and noticed that the port length is 12". The whitepaper suggests that there is an adjustment to the length due to port area, but I could not find a formula used to calculate this adjustment. BTW, is the adjusted port length measured along the centerline of port travel, in the case of a port with turns?

As always thank you for your thoughtful response.