I need someone's input on this. I got a 6th gen LX (I4) sedan and have an upgraded sound system in it. Recently I started getting a squeel/high pitch noise coming from the speaker. I know usually this is attirbuted to a bad ground wire somewhere in the system. It's very annoying at times. It's quite but gets louder as I accelerate. I think I've narrowed it down to the fron left side. All speakers are amped (4x50) plus subs (separate amp). I also have a second battery and a capacitor (1-F). Has anyone else had this problem and have you been able to solve it without taking it in to a sound shop? I just need to get it fixed asap cause it's driving me nuts Any info/help would be greatly appreciated! Thanks.