Crossover talk: How does it affect amp headroom?

I am currently implementing a set of subwoofers into my stereo system. I have decided on a DIY project, and I started looking into passive crossovers to wire up. I plan on running one 2-channel amp for my main speakers, and one 2-channel amp for my subwoofers.

I started thinking about headroom and amplifier efficiency. If I just have the passive crossovers in my speakers and subwoofers, the amps will both be working hard to send full signals to them, correct?

Would it make more sense to use an active crossver between the Pre and Amp stage to make it 'easier' for each amp to perform?

Anyone with crossover experience want to chime in?

Thanks in advance for any and all pointers!

Amps are load reactive, so a passive xover will reduce the load. However, a passive xover, espescially at low frequencies, is a load in itself and highly reactive and parasitic.

For the price, the active and flexible Paradigm X30 is an easy choice but I don't think Paradigm makes them anymore because they have switched over to active subs. Easy to find on the used market still.

It's generally easier to integrate using speaker level outputs but that also compounds error.