There is no one single "right" crossover setting even for the identical set of speakers -- the best setting will differ depending on the room, listening habits, and personal preferences.
Personally, I would always start out with the SMALL/80Hz setting all across, regardless of the bass capability of each speaker (unless yours are those tiny Bose cubes
). After carefully optimizing the speaker placements and calibrating the system with this textbook (THX-standard) starting point, I would then "live" with the setting at least for a week, so that I would be very familiar with the sound quality. Only after this, I would start tweeking the setting further.
In fact, there are good reasons why THX recommends the 80Hz crossover -- read
this excellent article.
