Presently using the Magnepan crossover. It is a two way external crossover. It splits into two signal. One goes to the mid and high, the other goes to the bass and mid bass.
I removed the ribbon tweeter form the Maggie panel and built a passive crossover using ClarityCaps CSA capacitors and Solen Perfect Lay inductors. When I get further along I will tweak the mid to tweeter passive crossover and upgrade the components.
I have a DBX Venu360 coming and will be able to biamp. I will use the Venu360 to get close to the correct parameters for a crossover. I have a Pass DIY biamp 6-24 crossover kit. I will probably end up with a PAss Labs XVR-1 before it is all over.