All frequencies travel down both runs of a biwire cable to the speaker. Low frequencies are not feed to the mid/tweeter due to the crossover as in single wire.
Where is the signal blocked?
In a Bi-Wire setup, where are the low frequency signals blocked on the cable going to the mid/tweeter? Are the signals stopped at the crossover in the speaker, or do they never travel down that cable from the amp? I suppose the opposite about the higher signal can be asked as well, having any effect on the low signal cable.