I do passive-aggressive bi-amping. I left the crossovers intact (albeit separated) in my AL-IIIs (primarily to take care of the ribbon notch), but have an active crossover in front of the amp channels driving them, so the amps are only amplifying the frequencies being reproduced by the speaker/ribbon. If I ever replace my woofers, I might bypass the low-pass filter for them, but I have enough power that I really don't need to. Moreover, I've often wondered about removing crossovers and the phase relationship that might change. I know that crossover designers are very cognizant of phase shifts introduced by the passive components in a crossover, and work very hard to get them the same in both the low and high (and, in three-way or more, band) pass filters. Therefore, removing one part of the crossover w/o removing it entirely might screw things up badly.
It should sound like it isn't there!
There is a difference between hearing and listening...
Making life enjoyable through expensive electronics.
Carver: C-4000 & C-1 preamps, PSC-60 preamp/tuner, TX-11a tuner, M-400 (2), C-500, M-500, M-500t, M-500t Mk.II, A-500x, AL-III loudspeakers (2 pr.)
Sunfire:Theater Grand III processor, Ultimate Receiver, Cinema Grand Signature 400 ~ seven, True Subwoofer Mk. II, D-10 Subwoofer