Left-Right audio "crosstalk"

Discussion in 'General Electronics Chat' started by ElectricMagician, Jun 5, 2014.

  1. ElectricMagician

    Thread Starter Member

    Jul 26, 2012
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    Hello everybody,

    I replaced the my laptop's audio connector today after accidentally breaking it. I have an odd problem, however:

    When I test the socket directly (by connecting a low impedance phone to the connector tips,) both channels seem to be working as they should. Things also seem alright if I plug in a standard 3.5 male-male cable to the connector and probe the tips .

    (channel order also seems alright: GND,R,L)

    However, if I connect any type of stereo earphone, I hear both audio channels from both sides, at roughly the same level.

    Also, if instead of the standard cable above I use the 4 ring M-M cable that came with my headphone, the "crosstalk" appears even when I probe the tips with the low z earphone.

    (interestingly, if I use the standard cable with the headphone, it still appears.)

    Is there an explanation for this?


    I tried introducing different value caps but all they did was filter out the treble.

    Your help greatly appreciated.
     
  2. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    "...both channels seem to be working as they should."

    Seem? Did you do the tests with left-only and right-only signals?

    ak
     
  3. ElectricMagician

    Thread Starter Member

    Jul 26, 2012
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    Yes, Gnd-L and then Gnd-R.
     
  4. ronv

    AAC Fanatic!

    Nov 12, 2008
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  5. ElectricMagician

    Thread Starter Member

    Jul 26, 2012
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    Using headphone:

    Left and Right messages heard through both channels. Center message plays very low.

    Using cable and transducer things work correctly.
     
  6. ronv

    AAC Fanatic!

    Nov 12, 2008
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    How many wires go to the plug? A picture might help.
     
  7. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    I understand that you were measuring left only and right only. But did both channels have audio on them at the time, or did you move the pan slider all the way to the left and then right so only one channel had audio on it at a time. It is the only way to do crosstalk measurements.

    ak
     
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  8. ElectricMagician

    Thread Starter Member

    Jul 26, 2012
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    Originally 4, fourth going to microphopne, but I didn't connect it.

    Note: something has changed now, left plays really low, center and right play loud (crossfeed still exists.)
     
  9. ElectricMagician

    Thread Starter Member

    Jul 26, 2012
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    I tried all sorts of measurements.

    When audio is routed to only one channel, it still plays on both channels, it gets a lot louder when it's routed to the right channel though.
     
  10. alfacliff

    Well-Known Member

    Dec 13, 2013
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    did you replace the audio connector with a 3 conductor stereo or 4 conductor stereo headphone / mic jack?
     
  11. ElectricMagician

    Thread Starter Member

    Jul 26, 2012
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    0
    4 conductor, although the fourth (mic) is not connected.
     
  12. Markd77

    Senior Member

    Sep 7, 2009
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    Unfortunately some of these sockets don't have the contacts in the correct places, try slowly moving the plug out of the socket and see if at some point you get the correct output or just output out of one side (it may be the wrong side though). If that's what's happening, try a different brand of socket.
     
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