I made 3-way active crossover circuit based on a project published in 'Electronics World', it was basically a 3-way subtractive cross-over. Its online version can be found at - 3-way subtractive X-over.
I made its PCB but when i run it, to my dissappointment, the output signal level was quite Low. Meantime i compared a subtractive crossover design as compared to a 24th order Linkwitz-Riley X-over, i decided to make a new filter based on Linkwitz-Riley design by Rob Elliot Project 09.
Its PCB is ready, just a little soldering is pending. Very eager to see it sing.