bi amp question

I'm with Fatparrot that there isn't any real difference which set of posts you hook up to. O'm sure that, if there is a prefered arrangement, the owner's manual will mention it. As to bi-amping using the speaker's existing HF and LF inputs (passive bi-amping), you'll need two amps of equal gain and the easiest way to accomplish that is to get two of the same amps.

Let us know how it works out for you.

Regards
Jim

Best bet is to input your cables into the tweeter input (in theory) but whether you will actually hear any difference is another matter! Of course, try both ways! Experimenting with equipment and system set-up is one of the many joys of our hobby (passion!)