RCA Jacks - Loud Buzz problem

Discussion in 'Car Audio Head Units' started by ddegagne, Aug 15, 2010.

  1. ddegagne

    ddegagne Member

    I have enjoyed my amp and head unit for a few years now but all of a sudden there is a horrendous buzz or hum when you turn it on. It is ok when the volume is turned to zero but as soon as you turn it up to even 1 it makes this awful noise.

    I have isolated the problem to the rca input jacks going between the headset and the amp. When I unplug and plug in these jacks at the amp, there is a loud buzzing noise and it makes the subwoofer move. I have checked the jack wiring and all seems ok, no breaks etc.

    I have directly grounded the head unit and still no luck.

    Any ideas on what is wrong?

    Don
     
  2. TheViking

    TheViking Well-Known Member

    I might start by pulling out the head unit. unplug the RCAs at the radio and see if the problem persists. If indeed the buzzing is still persistant, get another set of RCA cables and run them from radio to the amp..just dangle them in the car, this is just to see if your existing cables may have a short or have gotton pinched over time.
     
  3. ddegagne

    ddegagne Member

    Thanks Viking, already done that. Also, I have grounded the HU direct to metal and no luck. Could it be the amp input? The buzz (plus all sound of course) stops when you unplug the rca plugs from the amp or the HU.

    Don
     
  4. TheViking

    TheViking Well-Known Member

    Still sounds like a bad RCA cable...did you ACTUALLY run a NEW RCA cable from deck to amp? The amp will only do what its told by the input signal it sees.

    If you did as I asked and you still have a buzz emanating then might look at the Head unit as a source of noise. try borrowing a buddies radio and wiring it up and see if the problem exists. Not an easy check...but will guide us in the right direction. Might also try and isolate the ground for the radio and running the ground wire to the same point the amp is grounded. (this includes isolating the ant. connection , by unplugging it, and disconnecting the radio ground from any factory ground wire)
     
  5. ddegagne

    ddegagne Member

    I have installed a different HU and there is no problem with loud buzz. Accordingly the problem is not the amp or the rca plugs. It must be with the HU. I have cut the factory ground and connected the ground wire to metal.
    What next?

    Don
     
  6. TheViking

    TheViking Well-Known Member

    with the radio sitting in your lap or at least not touching anything metal...run the radios ground wire to the same point as the amplifiers ground...this might be a ground loop...simple term for different voltage potentials in the vehicle. It can induce noise into the sytem.
     
  7. TE5LA

    TE5LA Guest

    Try connecting a ground wire to the RCA shields near the back of the radio.
     
    Last edited by a moderator: Oct 9, 2010
  8. Bad_dude

    Bad_dude Member

    is it a Pioneer unit? Try grounding the RCAs. Both at the head unit and the amp.
    Good luck.