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Not Your Average Ground Noise!

Discussion in 'General Car Audio Discussions' started by playapimppro, Jan 11, 2007.

  1. playapimppro

    playapimppro Full Member

    Hey whats up guys i decided to install my voice amp the other day (6 channel audiobahn amp) and whatever me and a friend of mine did and everything was good, no noise and sounded nice, until i lifted the amp up from one side to play with the settings, and then reconnected all the bass amp wires , so then i went to turn on the car to see how it sounded with the bass amp and here it was a real badddddd ground noise! like its literally unbearable lol now what i dont understand is that when i first turned on the car with the amp it sounded fine no ground noise, so then i got so ****ed i ended up leaving it like that and decided to just by a couple of "ground loop isolator's" from ebay (3 in total considering it was a 6 channel amp, plus my bass amp, and judging upon how loud it was lol) well whatever the filters came in from ebay. first i connected 2 of the filters to the voice amp and the noise went some what down, but when i put the third filter to the bass amp it reduced it a lot, still not taking it off completely but enough to be able to actually have a conversation in the car (yea its really that bad), but then i noticed that when i would connect the filter to the bass amp, my bass would sound COMPLETELY different, it would sound horrible, like the filter wouldnt let it play low frequencies or just make it distort, i spoke to my cousin after that and he had said he had saw a groun loop isolator for bass amps on ebay, ive looked but nothing, also a couple of days after that i was playin around with the my (HU) Pioneer AVH-P6500DVD and i noticed a weird thing, some how when the brain of the HU is leaned against the metal of the car (ground) the ground noise goes down by more then half ?

    by the way i ran the power and rca's on separate sides, didnt share any ground terminals for any amps, made sure they were tight so they wouldnt jiggle, the more i rev the car the more it whines, and anything i turn on from the heat to turning signals it picks it up, none of the amps are touching the metal of the car (ground) oh and last but not least i drive a 1995 Cadillac Deville

    let me know what you guys think, because right now i have it running on literally 4 ground loop isolators lol and my bass sounds like shyt, and still have the dam ground noise that doesnt even drown out if i put the music up, my two guesses is that it has to do with the HU possibly being F'd up and my bass amp..

    but any input is greatly appreciated..
     
    playapimppro, Jan 11, 2007
    #1
  2. pedro quiroga

    pedro quiroga Well-Known Member

    start unplugging rca's one by one.then see which one's makeing the most noise.what happens when you disconnect the bass amp?any diffrence?

    the guys here will tellyou to ground your HU to where the amps are grounded.
    oh! double check ALL your connecttions.rca's and grounds.sounds wierd that it would do that after you only moved the amp a little.

    i had a pioneer 7700 and one day i lowered the rear seat to make an adjustment to one of my amps.so when done i put up the seat and BAM!! noise.very loud noise.the kind you are discriebing.

    it turns out my radio's rca outputs went bad.how.,i dont know. maybe i pinched something.i had to buy a new radio.
     
    pedro quiroga, Jan 11, 2007
    #2
  3. aznboi3644

    aznboi3644 Full Member

    Well I'd just try regrounding the head unit...I wouldn't go through the trouble of running a ground all the way back, maybe do that later after checking the rcas...and check the rcas one by one
     
    aznboi3644, Jan 11, 2007
    #3
  4. pedro quiroga

    pedro quiroga Well-Known Member

    i've seen most rca's have a third wire in them.is that to ground to the rear?
     
    pedro quiroga, Jan 11, 2007
    #4
  5. aznboi3644

    aznboi3644 Full Member

    some have a remote wire in there too for ease if wiring...but I never use it cuz its like 20 gauge crap wire that you can't even crimp
     
    aznboi3644, Jan 11, 2007
    #5
  6. pedro quiroga

    pedro quiroga Well-Known Member

    ah ok.goy you.so it can be both or none.your right it is too thin for anything
     
    pedro quiroga, Jan 11, 2007
    #6
  7. aznboi3644

    aznboi3644 Full Member

    not both or none...it is only the remote wire...but its way too small...if you use a but connecter it feels like the wire will break it is soooo small
     
    aznboi3644, Jan 11, 2007
    #7
  8. pedro quiroga

    pedro quiroga Well-Known Member

    i know.was just kidding....GOSH!!.lol
     
    pedro quiroga, Jan 11, 2007
    #8
  9. Willy D

    Willy D Full Member

    Playa....

    Do you have a hand held digital volt meter?? if not, can you borrow one??

    Once you have a volt meter, set it on DC volts....Set it for the scale closest to 12 volts.....Put the black lead on the negative terminal of the battery (make sure it has good contact here)......Next, check every place that you have an audio component grounded (HU, amps, etc).....If you go to the amps ground lug (right on the amp) and place the red lead from the meter there, see what your reading is.....It should be zero (or at very most .5 volts)...if you put the test lead there and show a reading of let's say one volt or higher, you have a bad ground.....

    Have you done the "big three?" if not, read this..

    http://www.caraudiotalk.com/audio-forum/showthread.php?t=3987

    All ground points on the car need to read "zero" when checked as I described..Take the filters off and throw them away...they are only a bandaid...if you have good grounds, good connections....then check the RCA's...If your HU is grounded good and your amp is grounded poorly, the ground will try to get from bad (amp) to good (HU) it will travel down the RCA which is much lower voltage than the 12 volts...If the RCA shielding is poor or damaged, you can get battery voltage leaking in causing the noise...Even though you ran the RCA (signal) and power wires on opposite sides of the car, they are all still contacting the biggest wire in the car...THE CHASSIS..

    First and foremost check the grounds.....check the grounds.....with a meter, not by eye or "looks good, tight and clean" cause the point of grounding (the component) may be a great connection, but what it is connected to may not have a good connection (path) to the battery....

    Willy
     
    Willy D, Jan 11, 2007
    #9
  10. Ranger SVO

    Ranger SVO Full Member

    Almost right, you use it to ground the chassis of the radio to the chassis of the amp. In some cases it will help to reduce noise.

    Now I have seen people use it as a remote turn on wire, PLEASE DON'T
     
    Ranger SVO, Jan 11, 2007
    #10
  11. pedro quiroga

    pedro quiroga Well-Known Member

    ok.i thought it had something to do with grounding
     
    pedro quiroga, Jan 11, 2007
    #11
  12. aznboi3644

    aznboi3644 Full Member

    oh ok...i was wondering why it was such a small gauge
     
    aznboi3644, Jan 11, 2007
    #12
  13. aznboi3644

    aznboi3644 Full Member

    aznboi3644, Jan 11, 2007
    #13
  14. Ranger SVO

    Ranger SVO Full Member

    I know it does, but I (and many other installers) do not like power wires (even low current) running dead center between the Left and Right RCA's. Just not a good idea.

    Most installes that I know (including myself) use it as I've previously stated.

    Many better amps (especially Kenwood) has a screw on the chassis that says ground. Well thats what its for.
     
    Ranger SVO, Jan 12, 2007
    #14
  15. aznboi3644

    aznboi3644 Full Member

    ahh icic....so you ground the chassis of the deck to the chassis of the amp???
     
    aznboi3644, Jan 13, 2007
    #15