Has anyone had any feedback from there aux input. I occasionally get a crack and in-between songs I hear a low ring, very low but noticeable when there is no sound. might it be my cheap cable I'm using or maybe because I'm streaming Pandora off my cell phone?? Any opinion. It's a 2011 c3 if that matters.

Its the cable. I thought mine was messed up too until my friend told me he already had to replace the cable twice.
Sucks but apparently these go bad often.