Bi-amping and passive crossovers?

Okay, if I'm going to run 4 channels to my front components (i.e. 2 channels to the front tweeters, 2 to the front woofers), do I need to use the outboard crossover?

Can't I just use the active xover's built into the amp?

Based on all the a/d/s stuff I've read, their wiring diagrams use their outboard crossovers too, but you need to cut the jumpers. If that's the case, aren't you basically bypassing the passive crossover anyways? :dunno:

As you can probably tell from my question, I'm a little confused.