Honestly, it looks pretty nice. The dip from ~300 – 3000 Hz is a product of the drivers themselves. The Epique naturally drops at around 250 – 300, and the Morel starts to drop around 2-2.5k. Have you tried dropping the crossover point? The Fs is 650, so 1300 would be the rule of thumb, but you could go down a bit lower. That’d help pull up that dip, maybe with some manipulation afterward to tame the high end instead of before the filter.