quick question

[Falcons]

im building a box for a buddy today and i have a design, just not sure on the port length. the way i have it designed is two subs on each side of the box and they share a slot port in the middle. now when calculating my port length, do i add up both walls ( left and right) to get it, or just one side?

[iamamp3pimp]

Port length is measured down the middle.

I hope this answers your question