Ground Loops

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi everyone this is a subject that I'm sure has been heavily discussed before but I would like to bring it up again. I have never quite understood what causes a ground loop in car audio I just know how amazingly annoying they are.. If some of you could expand upon them and enlighten me I would be very grateful.

My own experience is this, I drive a 98 Jeep wrangler and I originally had a Dual amp powering two Kappa 6x9s they worked I would say decent but I wanted an upgrade. About this time replaced my old alpine HU with a Kenwood mainly because of the iphone/ipod control it added. I bought two kappa speakers for inside the dash and cut the stock speakers out of their mount so I could put them in. After putting them in I realized the speaker ground was touching the mounts I made causing interference so I put electrical tape in between the points of contact. I built a down firing sub box to fit behind my rear seat with a 10'' alpine type r and a POS amp, kenwood 7204d, which i tried to hook up but never got real sound out of. I thought it was the amp so I went out and got a JL Slash 500/1 (which I am very happy I did) and I wired it all to my HU and powered with 0/1 gauge wire for maximum current. Now, it worked but the whole system shut when turned up loud with the car off and wouldnt work when the car was on it would just buzz. I decided to locate the problem so I hooked up a male stereo to rca jack to my amp and played music via iphone (worked like a charm) with car running or not running. I tried changing rca wires to the HU, no luck, and I tried grounding the amp and HU to the same point, still no luck. So I went out and bought myself a ground loop isolator, installed it behind the head unit, and decided to run the ground wires on it to the same ground point as my amp ground. This worked pretty well for awhile but now I am repairing my amp and want to know the truth, is there anything more I can do to solve this problem? And how much sound quality am I really losing by using a ground loop isolator, if any?

Can a ground loop be caused by a negative speaker input touching the car body and if so is my problem that i used electric tape to separate the two? Or is it just a bad Head Unit? You guys have been really helpful to me so far I'd love to hear some input
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.