I just got my first system installed and was looking to set the gains... i have a kenwood 9152d amp and on it there are only 2 knobs one is lpf frequency and the other is input sensitivity. Is the input sensitivity the gains? If it is... there are 8 different settings 5,4,3,2,1,.5,.3, and .2 (max) I know how to calculate my gains by reading the tutorial but how do i apply it to these settings?