I worked with building professional P.A speakers for DPAC and NPAC (Danish and Norwegian PA Centre), so I'm not a total noob in speaker design. Crossovers on the other hand, is not something I'm very skilled at, as all the pa stuff used active crossovers (digital).
If you want a near perfect, smooth frequency response, a passive crossover can get quite complicated, with L-pad, notch filters, baffle step correction in addition to the Hi-pass and Low-pass. And quite expensive too!
The x-over I'm most pleased with for this project, is getting close to £200 in parts for just the x-over
Designed another one with fewer parts, and pretty close response for around £70, which is probably what I'll go for.
I just want it to sound good, not exceptional
I'll post some pics when I get going.