Share 'Resonance strings'

Hi every one, I'm Alberto from Italy, I'v made a guitar with 12 resonance string under the fret board, like Mr Carlson ,and they are all 7 gauge, but I can't get to work. Please is there anybody con help me to find out the right gauge and the right note, for every resonatyng 12 string ? Thank you in advance to everyone that will take consideration Alberto www.albertobonafini.com