Gain equalization
 

With the gain amp in my 90, is there some type of equalization curve bult into it? like a LOUDNESS function to make the bass louder? I want to use the gain control as an input for my sub amp, but I dont want to go through all that and have bloated sounding bass. Is there a way to bypass the gain amp and use the slide switch only with the pre outs on my deck?

OK, would it be correct in assuming that if I hook up the Gain input to my 4 volt pre-outs on my deck, that I will get a resulting 1-3 volt output at the rear speakers? And is the output signal as flat as the standard output from the deck? I am worried that it has some sort of midrange bass-boost or something like that

What are those 4-volt pre-outs for? The gain lever is really designed for electric resistance, I wouldn't put sound through it.

I was going to send the signal from my preouts through the gain wiring in the dash and then bypass the amp. that way I could use the gain slider to control the input going to my sub amp. And still be able to use the line-level inputs. The whole point of this is so i can use the factory wiring as much as possible so I dont have to run new wires, and use the gain switch as a sub control. I want to bypass the gain because I think that it woudnt sound as good as if I used any factory parts (other than wiring)

See, the lever controls the amount of bass amplification that the stock bass amplifier puts out, so I think you would have to run the signal through the stock amplifier.

I dont think that you would have to go to the gain amp. I think that you could just bypass that, convert the wires going into it to RCA or not (your pref, depends on your sub amp) and run those to the back for the amplifier and subs.

how does the gain slider control the amp? Does it cut the input signal or does it activate an internal volume control inside the amp?

That, I am not sure. :(

The slider control is still a potentiometer, meaning it could be used for attenuating any analog signal within it's current and voltage limits. I beleive the control has has a plug with four wires on it, two most likely for the mono sub signal, and two for the nighttime backlighting of the control face.