tweeter whistles with rpm of engine?

hey guys, my front drivers side tweeter has a high pitch whistle that follows the rpms of the engine. its a 96 gt with the mach 460. i removed it and put a known good one in its place and still have the whistle. it only does this when the engine is on, and no its not the supercharger im thinking it could be my new alarm i had installed last summer, the sound had started that fall. other than that i have no idea, id like to find something to wrap the speaker's wires with to rule out interference. any thoughts? thanks guys

the head unit is a 4-5 year old pioneer cd deck. i never thought of the amp, i can swap the passenger one with the drivers one and see if that does it. thanks