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Thread: Ground loop isolator

  1. #1
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    Ground loop isolator

    I am designing my setup for a mazda rx8 and looking at people who have done projects in them to get as much info as possible. I see that people are using a ground loop isolator.

    What is this and why would I need one? How would I know if I need one? Where does it go in relation to the audio lines?

    I'm sure there is info about this on the forum, but I really do not have time to search, as I am in the middle of a bunch of class-work and shouldn't even be posting this, but it is dreadfully boring, so I had to do something of interest to me.

  2. #2
    Vendor - Qube colin's Avatar
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    Ground loop isolators are temporary fixes to engine noise. If you hear a whine in your speakers when your engine is running, a ground loop isolator will eliminate any DC voltage in your audio and therefore kill the noise. It doesn't address the problem but is commonly referred to as a "band-aid" for a ground loop.

  3. #3
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    Quote Originally Posted by colin View Post
    Ground loop isolators are temporary fixes to engine noise. If you hear a whine in your speakers when your engine is running, a ground loop isolator will eliminate any DC voltage in your audio and therefore kill the noise. It doesn't address the problem but is commonly referred to as a "band-aid" for a ground loop.
    okay. So what is a fix for the problem? Or I guess I should say the best fix?

  4. #4
    Neither darque nor pervert DarquePervert's Avatar
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    There is a whole thread in the Car Audio forum all about troubleshooting noise in your system.
    Have you looked in the FAQ yet?
    How about the Wiki?



    Under normal circumstances, a signature would go here.

  5. #5
    FLAC WuNgUn's Avatar
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    I've never had to use one in my car before...maybe I'm just lucky.

  6. #6
    Vendor - Qube colin's Avatar
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    If you design your system "properly" then you shouldn't need a ground loop isolator. It's a measure to cover up a problem. Hopefully you won't even need one. I say "properly" because sometimes there are grounding issues that are just far too difficult to solve due to chassis resistance and depending on the space that you have available. In those cases, you'd be better off using an isolator or other methods of transferring your audio (optical perhaps).

  7. #7
    Variable Bitrate quantum's Avatar
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    I used one in my setup as well, purchased at Radio Shack for about $20.00.

    My system was installed properly, taking into account short ground runs and all that fun stuff, but I was still getting a barely audible whine under 2000 RPMs. Just enought to make me nuts!

    My problem turned out to be the 1/8" headphone jack on the PC was a little worn, and the plug wouldn't make a solid connection (snap in) with the jack. If I moved it or bent it, the whine would go away, only to come back when I hit a pot hole or made a hard turn.

    The ground loop isolator was a 2 minute install, and solved the problem for good.


    GL with your project!

  8. #8
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    My car2pc adaptor just came today. So will this solve the issue(not sure if I'll even have the issue) or would I need the isolator too? I assume i will.

  9. #9
    Maximum Bitrate Injector's Avatar
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    Quote Originally Posted by colin View Post
    If you design your system "properly" then you shouldn't need a ground loop isolator. It's a measure to cover up a problem. Hopefully you won't even need one. I say "properly" because sometimes there are grounding issues that are just far too difficult to solve due to chassis resistance and depending on the space that you have available. In those cases, you'd be better off using an isolator or other methods of transferring your audio (optical perhaps).
    sometimes there is no other way around it, i spent 3 weeks and have a 4 page thread showing all the tests i did, i did everything from testing resistance on wires all the way up to using an external psu.

    Quote Originally Posted by mazda8;
    I'm sure there is info about this on the forum, but I really do not have time to search
    this is a big no-no, take it from someone who's been here a while, as soon as you say i don't have time you set the cross airs on you, you got lucky too, DP went easy on you.

  10. #10
    Newbie smartass365's Avatar
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    I hate to resurrect an old thread, but I didn't find anything on specific isolators.

    I'm having a ground loop isolator problem that's limiting my bass. A cheap isolator off of ebay killed everything, and the current stinger reduces my overall volume by about half while cutting out the very low end. It's rated for 20-20kHz, but it doesn't seem to make it anywhere close to that.

    Is there a particular brand that anybody's had a good experience with or something similar? Maybe a voltage follower op amp or alternative that's not transformer dependent?
    2003 Chevy S10
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