Using the Subwoofer Compensation Chart: How do

Discussion in 'Archived Threads 2001-2004' started by DaleI, Jan 14, 2002.

  1. DaleI

    DaleI Stunt Coordinator

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    Setting the Sub level. I use the Video Essentials test dvd and the Radio Shack SPL....

    I have the Radio Shack Compensation chart in front of me, but just how do you use it? I'm having trouble figuring out those Hz numbers down the left column of the chart. For example, at "20Hz add 7.5 db." How and where do you get the "20Hz?" I'm using VE so is its test sound a constant 20Hz? The SPL doesn't measure Hz does it?
     
  2. Zbigniew

    Zbigniew Stunt Coordinator

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    Dale,
    both VE and Avia do not have separate tracks for single tone, only sweeps.
    You can either download some simple tracks from internet good place to start is this thread:
    http://www.hometheaterforum.com/htfo...5&highlight=CD
    or get software to generate proper tones - simplest is NCH tone generator http://www.nch.com.au/action
    To register:
    simplest - SPL meter, pencil, paper (or computer and spreadsheet);
    more geeky - RTA like SpectraPlus or ETF5. Above mentioned
    thread include links to all of them.
    Enjoy calibration !
    _zjt
     
  3. BruceD

    BruceD Screenwriter

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    Dale,

    Simple answer is you don't use that correction chart at all with either VE or AVIA for calibration.

    To use the chart follow Zbigniew's links and suggestions.
     
  4. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    The RS meter reads about 2-3dB low during a typical subwoofer test tone(one octave 40-80).

    If you set all speakers to 75dB(for example)...including the subwoofer,then the subwoofer is set 2-3dB *hot*.

    TV
     
  5. DaleI

    DaleI Stunt Coordinator

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    Thanks. Does AVIA and VE know that the RS meter does that--reads 2-3db hot?

    I assume so since they suggest buying and using that SPL.
     
  6. DaleI

    DaleI Stunt Coordinator

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    Thanks for the info. Yeh, it would be interesting to know if they do because in future editions they would suggest setting the sub to 72 or 73db then--even though most prefer it a little hot.
     

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