bi amp imrpoving?

If you intend to do active biamping, you must (1) bypass or remove the crossover built into the speakers and (2) implement a custom-designed line-level replacement for it. This is not trivial as off-the-shelf crossovers will not do but it has become easier lately due to computer-based modeling of speakers and crossovers.

Kal

The downside is that it is hard to get it right. Often negating any benefit it would have brought.

Amen. That is what I meant to imply.

Kal

You can use one amp for bass and one for the highs & can still be passive. You can also use one amp for the left & one for the right. These differences are horizontal vs. vertical bi-amping.

Lots of articles around, such as this one

Kal - why do you need a custom crossover? What's wrong with a of the shelf active crossover like the NHT X2?

Mark