when you bi-amped (that is what you described) you spit to load to two speakers in each B & W; you want to conenct them back and let internal cross-over work. if you don't have the original connectors, use speaker wire to connect "+" to "+" and Ground or "-" to ground / "-". Bi-wire is using multiple wires and in most cases is completely worthless, because most people tend to over wire ( us a lower number gauge wire ( bigger) than is necessary) 14 gauge will handle 95% of speaker installations.
You probably will not notice any difference! most the sound is in the speaker
and B & W are excellent speakers.
Good Luck
Forest Man!