out of phase, please explain

Discussion in 'Archived Threads 2001-2004' started by itai, Jul 5, 2002.

  1. itai

    itai Stunt Coordinator

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    hi all
    whats phase? i understand dipoles use that, what exactly does it do, and what effect is resulted?
    i currently hang my dipoles on the back wall (no sides!...)
    and they sound great to me...
    thanks.
     
  2. BrianWoerndle

    BrianWoerndle Supporting Actor

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    Speakers move in and out to produce. If they all move out at the same time, they are in phase. If a speaker moves in while the others are moving out, it is out of phase.

    Dipole speakers have one in-phase and one out-phase driver in the enclosure. Think of it as a push pull relationship. One driver pushes, and the other pulls. This keeps the volume of air inside the same.
     
  3. itai

    itai Stunt Coordinator

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    thanks brian
    so what's the difference to in phase? what's it good for?
     
  4. Kevin C Brown

    Kevin C Brown Producer

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    If you get any of the Avia, Video Essentials, or newer Sound and Vision DVD calibration discs, they all give good examples of "in phase" and "out of phase."

    The reason why dipoles for surrounds are wired out of phase, is that the sound from 2 out of phase drivers cannot be localized to any point in space. That is typically preferred for surrounds because a lot of the signal sent to them during movies is of a more "ambient" nature and not necessarily directly part of the action that's occurring on screen.

    With drivers that are in phase, you usually get better imaging and a better sense that hey, that sound is coming from over there. Dipoles wired in phase aren't dipoles any more, they are bipolars.

    IMO, the *best* surrounds are those that can be configured any way you want: direct radiators (monopoles), dipoles, or bipoles. For multi-channel music a la DVD-A or SACD, usually you want direct radiators back there, or *maybe* bipoles if you have bipoles up front.
     
  5. itai

    itai Stunt Coordinator

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    gotcha!
    [​IMG]
     

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