Check out the High Efficiency forum. There are some tips there. I haven't been able to track it down but one fellow there built a 2235/2118/2404 combo. The stock cross-over from the kit supplier had serious problems, but a revised version from Madisound modeled extremely well. I have a hard copy somewhere but I don't know if I have electronic. I will hunt around. This was a true three way, not a two way with woofer, though you can stretch the 2118 a bit. JBL had a model with dual 2118 drivers and a single 2404 a good number of years ago. Can't give you a model right now because my literature is packed away in a box somewhere.If you want more info, holler, and I'll see what I can find.
Dan