1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

How to eliminate electrical hum in stereo

Discussion in 'Car Audio / Security / Electronic Accessories' started by wikedeye, Apr 3, 2009.

  1. wikedeye

    wikedeye Well-Known Member

    Messages:
    1,772
    Likes Received:
    57
    Joined:
    Dec 14, 2006
    Location:
    Savannah, Ga.
    I installed a stereo in my car a while ago and the ground to the head unit was bad. I ran a new wire from the head unit and connected it to where the stereo frame and the floor pan meet (the bolt that holds the dash to the floor). Now I get hum in the speakers occasionally. Is it just that where it is ground is not a good spot or could it be something else? Where is a good ground spot? Would finding a better spot fix the problem.
     
  2. AHHVTEC

    AHHVTEC Well-Known Member VIP

    Messages:
    13,122
    Likes Received:
    245
    Joined:
    Oct 13, 2006
    Location:
    Alabama
    just beef up and get a better ground
     
  3. wikedeye

    wikedeye Well-Known Member

    Messages:
    1,772
    Likes Received:
    57
    Joined:
    Dec 14, 2006
    Location:
    Savannah, Ga.
    A better wire or a better spot? Where is a good spot?
     
  4. AHHVTEC

    AHHVTEC Well-Known Member VIP

    Messages:
    13,122
    Likes Received:
    245
    Joined:
    Oct 13, 2006
    Location:
    Alabama
    as long as its on the metal of the car it should be fine, but beef up the wire, it sounds like it dont have a good connection
     
  5. wikedeye

    wikedeye Well-Known Member

    Messages:
    1,772
    Likes Received:
    57
    Joined:
    Dec 14, 2006
    Location:
    Savannah, Ga.
    Ok thanx for being the only guy who helps people out nowadays.
     
  6. AHHVTEC

    AHHVTEC Well-Known Member VIP

    Messages:
    13,122
    Likes Received:
    245
    Joined:
    Oct 13, 2006
    Location:
    Alabama
  7. Luis998

    Luis998 Honda Enthusiast

    Messages:
    2,867
    Likes Received:
    55
    Joined:
    Jan 14, 2008
    Location:
    Orlando, Florida
    Hey Conan, I JUST saw this post. What your getting, I have learned, is called "alternator whine". What gauge wire are you using? I would suggest at least using an 8 gauge, though personally I usually go with 4 gauge, just in case. I'm trying to remember how my audio guy fixed mine which I think he moved where my power wire was routed in the engine bay as well as where my ground wire was connected to. I'm not sure if this will help but that is what I can recall. Good luck my friend. :thumbsup:
     
  8. wikedeye

    wikedeye Well-Known Member

    Messages:
    1,772
    Likes Received:
    57
    Joined:
    Dec 14, 2006
    Location:
    Savannah, Ga.
    I dont remember what guage it is exactly, but I know it was thicker then what was used in the original harness. I might not have to work today so if I dont I will take a look and try to fix it.
     
  9. MthaFuknGreen

    MthaFuknGreen Green on the scene.

    Messages:
    3,166
    Likes Received:
    32
    Joined:
    Oct 1, 2008
    Location:
    Lodi, CA
    get a bigger ground wire and sand clean the spot your ground is attached too and make sure its nice and snug on there. make sure you didnt route your power wire along the same side of the car as that audio wires.
     
  10. wikedeye

    wikedeye Well-Known Member

    Messages:
    1,772
    Likes Received:
    57
    Joined:
    Dec 14, 2006
    Location:
    Savannah, Ga.
    I am not using an amp or subs, just factory size speakers and a head unit.
     
  11. MthaFuknGreen

    MthaFuknGreen Green on the scene.

    Messages:
    3,166
    Likes Received:
    32
    Joined:
    Oct 1, 2008
    Location:
    Lodi, CA
    oh.. lol
    reading>me.

    try grounding the negative on the speakers directly to the frame near them.
     
  12. TommyTheCat

    TommyTheCat Gonzo Scientist

    Messages:
    1,248
    Likes Received:
    11
    Joined:
    Sep 29, 2002
    Location:
    Minneapolis, MN
    Whoa - dont ground any of the signal/power wires jackass. And you dont need much more than 12 guage wire to ground a freaking headunit guys.

    Are you getting just a hum or is it like a whine that changes frequency with your rpms? One is just a weird electrical loop while the other is noise from the alt (which im guessing you dont have). You said you only get it "occasionally" - can you elaborate on this?
     
  13. wikedeye

    wikedeye Well-Known Member

    Messages:
    1,772
    Likes Received:
    57
    Joined:
    Dec 14, 2006
    Location:
    Savannah, Ga.
    It is actually alternator whine (changes frequency with rpms). I dont usually notice it while driving forward, but if I reverse there is no mistaking that it is there.
     
  14. MthaFuknGreen

    MthaFuknGreen Green on the scene.

    Messages:
    3,166
    Likes Received:
    32
    Joined:
    Oct 1, 2008
    Location:
    Lodi, CA
    who said anything about grounding the signal or power wires?
     
  15. TommyTheCat

    TommyTheCat Gonzo Scientist

    Messages:
    1,248
    Likes Received:
    11
    Joined:
    Sep 29, 2002
    Location:
    Minneapolis, MN
    You did when you told him to ground the negative of his speaker. Sorry I dont know what you would refer to the speakers' signal/power cable (since it transmits signal or power).
     
  16. CRX-YEM

    CRX-YEM Super Moderator Moderator VIP

    Messages:
    4,623
    Likes Received:
    54
    Joined:
    Sep 29, 2002
    Location:
    Wallingford, CT
    To get rid of alternator whine you need a bipolar bypass capacitor, also the ground point to the frame of the car make sure it's got a really good contact sand away a bit of the paint and use dielectric grease. Also it might be quite possible that the point you chose for a ground is creating a ground loop.
     
    Last edited: Apr 8, 2009
  17. newb

    newb phresh VIP

    Messages:
    3,967
    Likes Received:
    179
    Joined:
    Sep 17, 2007
    Location:
    Backwoods Northwest
    Another common problem with ground wires is their length. Just somethin to consider.
     
  18. wikedeye

    wikedeye Well-Known Member

    Messages:
    1,772
    Likes Received:
    57
    Joined:
    Dec 14, 2006
    Location:
    Savannah, Ga.
    A capacitor is a bit overkill for my problem, but I will check the ground point and make sure it is clean.
     
  19. CRX-YEM

    CRX-YEM Super Moderator Moderator VIP

    Messages:
    4,623
    Likes Received:
    54
    Joined:
    Sep 29, 2002
    Location:
    Wallingford, CT
    the bipolar cap is a very small one just to block the alt. noise. It's not one of these overly huge caps used in monstrous audio systems.
     
  20. awptickes

    awptickes unimpressed by you VIP

    Messages:
    9,272
    Likes Received:
    497
    Joined:
    Aug 29, 2007
    Location:
    MD
    1 person likes this.
Verification:
Draft saved Draft deleted

Share This Page