IMO OUTBOARD (PASSIVE OR ACTIVE)THE BEST TO FLY WHEN PROPERLY SET UP.
Older Maggies and Emerald Physics had outboard passive XOs. Ignorantly, if not stupidly, both provided jumpers so short, that the XOs rested on the speaker bases (or in he case of Maggies), mounted directly to the back of the speaker, which means the XOs vibrated like crazy, as they do when inside the speaker cabinet
Proper setup would/should include jumpers long enough to clear the base as in the case with EPs and have their own iso bases
hth