The results are in:I was very pleased with the performance of the 12π basshorn subwoofer. I expected it to do well, but from everything I've seen, it appears to be the most powerful commercially available subwoofer on the market. So I am really excited about that. The frequency response was exactly as expected, and the push-pull configuration provides improved distortion reduction, particularly at very low frequencies where the horn is no longer able to reduce driver excursion.
The heat exchanger performed very well. Notice how the response curve of the 12π basshorn looks exactly the same at all power levels. We ran tests well beyond the limits of the device, but the response curve always looked exactly the same. Compare with other horns having no heat exchangers, and you'll see their LF response changes at high power levels. This is because motor heating changes the electro-mechanical specs and tends to shift the alignment towards an underdamped condition. Not so on the 12π, it's heat exchangers make performance rock solid, and the response is uniform at all power levels.