I'm just curious, with an Sryke AV-15 in the right box, which commercial sub would be somewhat comperable? (I'd be running about 750wrms approx 1300w peak)
The Adire Audio Dharman is equal to a Velodyne HGS15, so I'd imagine an AV-15 with PR's could easily outgun the HGS18. Hell, a Tumult in a sealed enclosure, an LT and the right amount of power will be pretty close to dual HGS18's.