OK...I seriously screwed something up here. I built a 120L sub with a Dayton Titanic mkIII with two Adire Audio 15" passive radiators loaded with an additional 1015 grams (1300 grams total) each. Based on Unibox and WinISD Pro, I should not have come close to the excursion limits of the PRs. This is kind of a drag as I have now destroyed $200 worth of passive radiators, about $50 worth mass supplies, and alot of time and effort. So much for my first PR effort Any ideas? At no time did the amp clip or the Titanic show any signs of distress. I guess its time to go back to ports.