Ive got a couple Orion amps. 4 2500ds and an 8004. Alot of people used to run them before FI hit the market. The rage woofers were the H2, RE MT and XXX and of course the DD 9515s. Everyone runs the DC and FIs now because you get an awesome woofer at a good price. Why pay more for the same performance. And I'm sure steve running the Fi's doesnt hurt at all.