Just bench tested the actual sound board. I used a 2" transducer first and the sound was not so good. Next I tried the two, 2" speakers and WOW!!!! When the deep rotor wash, they made for me kicked in, the hair on the back of my neck stood up. They even set it up so it is independent of the throttle.
The folks at Model Sound are great to work with and I highly recommend their sound board.
Jim