ZD, note that the question concerns removal of the speaker's crossover.
Biamping, whether vertical, horizontal, or in any other configuration which may be imaginable, does not eliminate the need for a crossover.
If the speaker's crossover is removed, then an active (electronic) crossover must be inserted between the preamp and whatever power amplifier channels are being used to drive the high frequency and low frequency sections of the speaker. The characteristics of the active crossover would preferably and presumably be chosen to mimic the characteristics of the speaker's passive crossover.
If no crossover is used at all, among other consequences the treble driver is likely to be blown up by the bass frequencies that would be sent into it, unless the driver is protected by a fuse which succeeds in blowing first.
02-27-15: Zd542
You have to be really careful when you biamp because its much easier to get bad results than good ones.
Well said!
Regards,
-- Al