In Feb 2010, a friend of mine who manufactures small runs of high-performance woofer drivers asked me how well I knew Hornresp. "Pretty well," I responded. Seeking to build a set of high-performance sound reinforcement subwoofers for a client, he and I embarked on a months-long design exercise to design a state-of-the-art dual-18" subwoofer using a quasi-horn-loaded sixth-order bandpass design and what I feel are among the most advanced 18" pro audio drivers available. The development of the enclosures led to minor improvements to the drivers themselves, a benefit of using small-run, built-to-order drivers. This project is currently progressing to the manufacturing phase.
(This page may describe a future commercial product; as such, build plans will not be made available. There will, however, be a few pictures.)