Get an Octavio pedal. From your bass effects pedals split the signal sending one side into the Octavio and then to a guitar amp while sending the other side into your regular bass amp. Profit.
No, i ment as in the me (lead guitarist) will be soloing in dual harmony with the rhythm guitarist, so hes playing the lower notes of a minor 3rd or watever... and the bass will take over the rhythm while we are doing that harmony...
Here's what ya need> A Fission> http://www.fishman.com/product/fission-bass-powerchord-fx-pedal