my car amp is producing "fuzz" through my speakers, like a radio does when theres low

[Linden G]

signal. Any ideas why? ive checked my head unit, its not the radio, its produces the same "fuzz" noise when playing a cd, also the music comes in and fades to the "fuzz" noise. im suspicious of my power feed being too small, could that be it? i also checked the earth, it looks fine. any thoughts would be appreciated

 

[Karan B]

you have installed a low quality audio output cable which runs from the back of the deck to the amp...the fuzzing noise is static and increases as you accelerate due to poor insulation of the cable