DoubleHeadphoneDistributer

Discussion in 'The Projects Forum' started by mpuvdd, Sep 21, 2007.

  1. mpuvdd

    Thread Starter Active Member

    Feb 11, 2007
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    Hello everyone,
    I'm working on building a small circuit to simply distribute an audio signal from an iPod, to two headphones. How would I go about balancing the headphones (cause they could have different resistances), and do you think that the signal would need amplification?
    Thanks for all the support,
    mpuvdd
     
  2. mozikluv

    AAC Fanatic!

    Jan 22, 2004
    1,437
    1
    here's a very simple circuit for that. improvements are welcome:)

    moz
     
  3. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
    10
    The headphone drivers have 16Ohm each. Did you took that into account? It seems that a lot of signal will be lost.
     
  4. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    You can buy them with individual volume controls for around $5 - $10 US. Anything you can build would be big and ugly. Google "headphone splitter volume control".
     
  5. mpuvdd

    Thread Starter Active Member

    Feb 11, 2007
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    Cool, well alright, I geuss I'll probably buy one since they're so cheap.
    Thanks for all the help guys. :D
     
  6. Ashok Gupta

    New Member

    Sep 25, 2007
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    0
    simply connect the two headphones in parallel.
    There is no need of amplifying the signal as power requirement of the headphones is very low.
    I think that there is only little variation in the impedance of two headphones.So u may match the impedance but it is not necessary.
     
  7. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    If the headphones are from different manufacturers, or are just different models, the impedances could be very different.
     
  8. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    If there is an impedance mismatch, the audio signal will be distorted; particularly at higher volume levels.

    The impedance of iPod headsets is 32 Ohms; standard headsets are 4 or 8 Ohms. Obviously, the iPods' output was designed to work optimally with an iPod headset; I can only surmise they chose 32 Ohms as a power-saving and/or weight-saving feature.

    In order to properly match other headsets, you'd need to use a matching audio transformer at the very least. Attempting to connect a low-impedance headset would certainly result in a great deal of distortion at higher volume levels.

    As a reminder; keep the volume low enough so that you can hear ordinary conversations above the music - otherwise, you will likely cause irreversible hearing damage.
     
  9. Brennn10

    New Member

    Sep 13, 2007
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    could I use 2 3.5mm line sockets, connected to a male headphone jack?
     
  10. Brennn10

    New Member

    Sep 13, 2007
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    So I stripped my stereo plug, now how do i connect it to the two stereo inputs?
     
  11. SgtWookie

    Expert

    Jul 17, 2007
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    A stereo headphone will have three or four connections. One or two are signal ground, the others are +right and +left.

    A 1/8" stereo plug has three connections. There are three areas of connectivity on the plug; the tip (+left)), a band near the tip (+right), and the signal ground.

    This page has a lot of helpful information:
    http://www.headwize.com/faqs.htm