Audio Systems: speaker distortion, amp line, pioneer head unit

Question
I have a new pioneer head unit deh-p7700mp I recently installed two brand new pioneer 5-way 6x9s in the rear dash.  I first hooked up a kicker 120.2zx on them when the car was on you could hear a whining noise that got louder with acceleration and also when the car lights are on the noise gets thicker I hooked up my sony 1200xplod on them turned the gain down almost all the way but the noise can still be heard just not as much you dont hear it when the amp is on low pass but you hear it on high pass what can i do to eliminate the noise because I know the output level needs to be turned down but should it be turned completely down I mean then it seems as if the speakers aren't even on a amp.  what do you think?  At the same time I haven't been able to turn the radio all the way up because of where I live if I could with the output levels turned all the way down would there be a signifigant difference between the speakers being on the amp versus running from the deck i mean thats the whole purpose of the amp is to get a louder stronger sound I'm trying to be heard ya feel me?

Answer
The amp connected to the speakers should just give more power.

I think what you have is the output of the preamps too high level at the input of the amp, or the amp maybe has a mic level input that you are using (wrongly).

There is clearly too much gain in the system.  Don't confuse voltage gain with power level; in your case you must balance the input to the amp so as not to overdrive.  Check the inputs carefully. If necessary you can add an attenuator.

The whining noise is electrical interference getting in the amp line.  It can be from too much gain as above, or from wrong wiring.

Hope you can track it down.
Cleggsan