Building a crossover from a schematic sounds easy until you try to fit everything on a board in some logical way and avoid cross-wiring anything:) Solder the crossover elements' leads directly to each other wherever possible. Where they can't be connected directly it's helpful to use white insulated wire for any positive leads and black insulated for any negative leads. I like to use perf board with wire ties to hold the parts in place.

The link below is a tutorial on building crossovers that you might find helpful.

• Crossover Construction