Hey Ron; I did no measuring with Colin, I jsut looked up the plans and made the port accordingly, isn't the best looking but who cares. I set up the horns to Altec specs, 4.5 inches from the front of the cabinet, the 511 setup is flush with the front. I won't tear these down for a long time. I still have a bunch of work to tighten up the cabinets but they will do just fine. I left you a phone message to see if you had a spare bed My wife thinks I am trying to start a local movie house. I will say the bass is superb, with my volume set at 12:00 I can't hear a thing outside of my room, darn the bad luck,