Whinning noise when I turn on my radio., I probably know the general answer. Options

[UTSlickVic]

Ok guy/gals,

When I turn on my head unit (CD/radio/sirius/etc) I hear some feed back whinning noise coming through the speakers. And when I change CD tracks I can hear a garbled track-change noise through the speakers (it use to be I just heard this coming from the unit itself, never though the speakers). It has never made this noise before. The last thing I did was the premium 8 speaker set up (with stock amps) and it never made that noise before.

Now for the kicker (and I maybe waaay off base but...) I THINK this noise started when I recharged my a/c freon. I remember recharging it and when I turned on my car the a/c was COOL but I noticed that whinning noise. I may have put too much.... anyways. Am I retarded or something? If not, let me know.

Anyways I'm guessing its a grounding isssue..... sigh But where do I start? I mean dang its been awhile since I messed with my system. Im really dont want to go around and check every wire.

PS: Would having mutiple grounds be causing this?

Thanks