I am going through each of my designs with the Smith & Larson system, importing the Spice model and making measurements to see if any optimizations are possible. The four π was first, and I'm getting ready to double-check the three π. I expect the same crossover from the four π should be what is best for the three π because the HF horn/drivers used are the same and the baffle spacing is approximately the same. But it can't hurt to check, and it's the next one up. Then I'll do the six and seven π models. As I said, I don't expect to find much movement there.