1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Audio noice filter, can't get rid of it

Discussion in 'Gen 2 Prius Audio and Electronics' started by Victorio Mo, Apr 9, 2015.

  1. Victorio Mo

    Victorio Mo Member

    Joined:
    Oct 6, 2012
    110
    29
    0
    Location:
    Folsom, California
    Vehicle:
    2008 Prius

    I have 2009 Prius and when I do plug in my Galaxy thru 3.5 Aux I have a lot of noise from engine,
    I tried those but nothing helped:
    (those I used while trying to charge my Samsung from car power, otherwise it works OK)
    1. Audio filter on 3.5mm line ( PAC SNI-1/3.5 Noise Filter from Crutchfiel $20)
    2 Power noise filter from ebay/china $7 which I install on front outlet

    I read success stories for those device on other vehicles, start thinking maybe Prius/Hybrid is special ?
    Or maybe my Samsung Galaxy 3 (I use Music Folder Player on it) is special too ??
    Appreciate your feedback, stories

    Vic
     
  2. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    7,475
    4,373
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Seems likely to me it's your charger putting out high frequency noise. Get another charger and try it.
     
  3. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,038
    10,012
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Some questions to clarify the situation:
    (1) do you have two cables plugged in, one for power (to the 12V socket) and one for audio (to the AUX jack)?
    (2) if so, then does the audio clean up (noise go away) when you unplug the power cable and run on battery only?

    If yes to both, then you are suffering from a 'ground loop'. Several other threads have discussed this, but I don't recall if any of the parties came back confirming particular solutions.
     
  4. 69shovlhed

    69shovlhed Surly tree hugger

    Joined:
    May 13, 2012
    2,170
    744
    0
    Location:
    Delaware
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    I did buy a ground loop isolator from ebay and it helped a lot.
     
  5. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    257
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    Or try it for a minute without the charger altogether.
    That should rule the charger in or out real quick.
     
  6. dhancock

    dhancock 2 Prius Family

    Joined:
    May 21, 2007
    357
    40
    0
    Location:
    Hamburg, NY (Buffalo area)
    Vehicle:
    2011 Prius
    Model:
    Five
    Like 69shovlhed said, you are having a problem with a ground loop (it's not the charger). What is happening is that the Galaxy audio ground is different from it's power ground. When you connect those grounds together noise (from the car's inverter) travels between these two grounds, coupling the noise into the audio. The solution is a Ground Loop isolator, such as this one from Amazon or this one from Radio Shack (that is the one that I have in my 2007) - if you can find a store these days.


















    w
     
  7. waynethexplorer

    waynethexplorer Junior Member

    Joined:
    Sep 8, 2015
    7
    1
    0
    Location:
    Alabama
    Vehicle:
    2008 Prius
    Model:
    Five
    In my experience I noticed the noise going away if you unplug the power on the device, no noise if just using the battery of the device, clearly a ground loop problem. Here’s something I did to have a dedicated music player in the car (not ideal for a phone you carry around) I bought an old Samsung galaxy s3 just for this purpose. First a rerouted the headphone plug by plugging a cable in the center console and running it to the glove compartment. For power I tapped into the cigarette plug under the dash, I ran this wire to a NO side of a relay. Then I found a constant 12v wire under the steering wheel and wired it to the NC side of the same relay. Then to activate the relay I used the switched 12v at the cigarette plug I was already using. The output of the relay was wired to a cigarette plug that I placed in the glove box. So to sum it up I had a place to plug power and an audio input in the glove box, except the power was switched in a special way. When the car was running the power was disconnected from the music player (the old s3) this allowed it to play with just the battery and no noise interference. Then when the car was off the constant 12v would connect to the player and charge the battery. So it was always ready to play with a fully charged battery when the car was started and no ground loop noise. I have since traded the car (regrettably so) and I wonder how confused the new owners must be if they try using the charge wire in the glove box...
     
  8. Kevin_Denver

    Kevin_Denver Active Member

    Joined:
    Mar 18, 2016
    581
    421
    1
    Location:
    Denver, CO
    Vehicle:
    2009 Prius
    Model:
    N/A
    Three things will help:
    1. Ground loop isolator
    2. Different Phone Charger
    3. Tying the grounds between your phone and the Prius' audio system more strongly together.

    How I did number 3 when I installed my aftermarket headunit is I connected the ground wire of the CD player both to the factory ground wire, but also ran a 12 AWG. wire to a nearby chassis bolt. If you wanted to do this on the factory headunit, you'd obviously need to take apart the dash, but it could be worth it. Basically, the less electrical "distance" between the phone charger and the headunit, the less noise will be induced.