Hey cbbuntz,
thanks for sharing your stuff, although I must admit that I have absolutely no clue how your filter works, even after spending quite a while with your schematic.
All I can say that your mixed phase crossover does work, the bands split nicely at the correct frequencies and they add up to unity. Very cool!
There is room for optimization, though. Regarding delays check out KohuGaly's post in the Downloads section at
Flowstone Guru. tan(x) etc. can be evaluated much faster, check out my Math Functions download at FS Guru.
I am still intrigued by your schematic, it is clear that you have put a lot of brains and effort into it, however I don't even understand the very basic idea behind it.
Please could you explain, or point to a reference?