JACKSONjs32

I'm trying to program my line 6 120 watt spider3 amp to use channel a or b to have clean sound & then switch to either channel c or d for a metal sound & have them be set at the same volume,BUT.. it's not happening,the metal is 10 times louder,ive done everything including turning the channel volume all the way down when programing the metal channel. I'm really getting irritated. How do I get these a,b,c,&d channels to be at the same volume??