Nah, that's what the gain's for. That just indicates the signal strength from the HU. Once it gets to your amp, you adjust the input sensitivity (just in case: that's what the gain control is). A higher voltage signal through the RCAs will be less susceptible to noise.
Don't worry about it. Noise as in DC input from from your power wire. A low pre-out voltage won't mean you will have a problem with noise, but you just have to keep your RCAs away from the power wire. I believe mine are 2 volt, and I can only hear a little noise when no music is playing. Twisted pair RCAs are a good idea.
o aight, well my rca's are ran on the passenger side of my car, and the power wires is ran on the driver side. so i guess i wont have any problems there.