I checked sizes of the cabinet panels I precut some time ago and they would make 34.25 x 17.5 x 9.25 for the inside dimensions. Plan's
description of the port leads to believe these are outside
dimensions. Am I correct all three numbers are outside dimensions
with wall thickness of .75" ?

I have JBL 2226J and 2426/2370, been looking for JBL 2012 for a decent price but couldn't see for any price;what would you recommend with
this woofer/tweeter combo as a midranger and what L2 value/tweeter
polarity.

Thanks, Michael