My buddy bought this unit and it has 1 2.5volt preout. After he had it installed his bass has become almost nill. Ive messed with all of the settings and cant fix it. Only way to get any output is to turn the amp gain all the way up and then its still weak. What im looking for is a product that will take that 1 rca preout and make it into 2 now and up the voltage. He wants me to install him 2 new amps. One for the sub and one for the componets we just ordered him. What am i needing. Is this even possible. I really wish i could talk him into getting rid of that unit for something better.