one point ground vs. multiple...

**Rocker298** · 03-30-2004, 09:10 PM

ok, so here is my question, i have been reading up, and many of you say to have everything grounded to the same point, and yet many other of you say that that is how a ground loop starts, well, i have a ground loop, and i have tried all to one point and all seperate points, i wouldnt really like to get an isolator since i have been told they dont work very well either. i have just tried everything i could think of without getting anything new. plez hlp!!

**DavidL** · 03-30-2004, 09:13 PM

did u try to pull the antenna wire to see if you have a groundloop there?

**kalito** · 03-30-2004, 09:41 PM

try doing a search on www.the12volt.com they have a car audio forum there...

**falconey** · 04-01-2004, 11:21 AM

need more info. how do you know you have a ground loop...what's your setup from car audio to carputer? Where is your ground point and are you sure it's scraped clean of paint? Answer these questions and i can try to help you out. To answer you're general question though it is best to use one ground point. Think of it this way if you used multiple then the current would have mulitple options as far as which route it wants to take(and it will take the best grounded route), but if there's only one point then it has no choice. That's simplest way to explain it.

**tom2112** · 04-01-2004, 01:24 PM

Gotta agree with Falconey. One ground point is the way to go.

When I was in the Army, all the equipment in the command trailer was grounded to one place. And that was a lot of equipment! I'm talking over 8 FM radio transceivers, satellite transceiver, a 4 wire phone system, a 2 wire phone system, cell phone tranceivers (the Army called them MSPSR or something stupid like that), computers, etc.

My point is: all that expensive electronic gear (some of it was pretty sensitive) was all grounded to one point outside the truck. That wasn't because we were too lazy to drive another ground rod either. It was standard operating proceedure. Believe me, that if the Army would have thought it would have been better for the equipment to have more grounds, my olive green covered butt would have been out there pounding more ground rods.

**bambooracer** · 04-01-2004, 01:44 PM

This link was posted in another thread. Seems well written and thought out:
http://forum.sounddomain.com/forum/u...c;f=5;t=008251

and the "big 3" upgrades refered to in the post:
http://forum.sounddomain.com/forum/u...c;f=5;t=007801

Good luck, and please let us know how you solve it!

**falconey** · 04-01-2004, 03:51 PM

The article is good and the one thing I would have mentioned if I knew exactly what this guy's sound problem was, is that it's pointless to run grounds from the head unit(if this is his problem) back to the trunk. It can be grounded in the dash area somewhere along the floor pan. To me it's pointless to run the ground wire back to the trunk. That being said if he has different equipment in a close area (i.e. two amps and computer in the trunk)...it would be a good idea to just ground at one point.

Still would need more info to help him out though, because really doens't give his setup or what kind of noise he's getting or what circumstances he get's it under.

**sfay93** · 04-01-2004, 04:08 PM

Could be something as simple as having his power wires ran next to his RCA wires. That will give you some noise.

**falconey** · 04-01-2004, 04:09 PM

Yeah well it's all speculation until we get specifics.

**Rocker298** · 04-02-2004, 03:18 PM

ok, sorry it took so long, i know i have a ground loop because i have my pc setup as a console between the seats, and i have mounted a couple of cig lighters on it, i have a mp3 player and a car charger, whenever i play the mp3 player through the fm modulator without it being plugged in its perfect, but when i plug it in it gets bead, i can hear the hard drive of the mp3 player and such. ive tried grounding all to one place, and to, as one person recmended, each one about an inch apart on the bare floor of the car, they both do the same, and i am sure it is ground loop. my setup is this... i have a 70a dc-dc to an itps, then from that feeds my computer then to that the audio gets sent to a fm modulator then to my head unit, i have no amp no subs or anything like that, i went out yesterday and got a usb sound card and it did reduce the noise silghtly but not to waht i would like. i think i have answered all the questions, and thanks for your help