bi amp imrpoving?

In that case, if properly implemented and adjusted, you can expect to hear significant improvement in practically all areas of sound.

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