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Radio Shack SPL meter correction

Discussion in 'Home Theater Projects' started by Nathan Stohler, Jan 28, 2004.

  1. Nathan Stohler

    Nathan Stohler Second Unit

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    I bought the digital version of the Radio Shack SPL meter a few weeks ago. I was planning on generating some tones to check the frequency response of my speakers.

    I've seen various correction charts for the analog version, and I was wondering:

    1) Do these charts apply to the digital meter?
    2) Does anyone know if the correction factors are indeed necessary?
    3) If so, can someone point me to a reliable chart?

    Thanks in advance.
    --Nathan
     
  2. Steve Griswold

    Steve Griswold Stunt Coordinator

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    While we're on the subject, I have the "new" analog meter from Radio Shack. Does anyone know if this is subject to the same corrections as the old one?
     
  3. Wayne A. Pflughaupt

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    I haven’t heard, so I can’t say.

    Here are the correction values.

    10Hz +20.5
    12.5Hz +16.5
    16Hz +11.5
    20Hz +7.5
    25Hz +5
    31.5Hz +3
    40Hz +2.5
    50Hz +1.5
    63Hz +1.5
    80Hz +1.5
    100Hz +2
    125Hz +0.5
    160Hz -0.5
    200Hz -0.5
    250Hz +0.5
    315Hz -0.5
    400Hz 0
    500Hz -0.5
    630Hz 0
    800Hz 0
    1KHz 0
    1.25Khz 0
    1.6KHz -0.5
    2Khz -1.5
    2.5Khz -1.5
    3.15Khz -1.5
    4KHz -2
    5KHz -2
    6.3KHz -2
    8KHz -2
    10Khz -1
    12.5KHz +0.5
    16KHz 0
    20KHz +1


    1/6-octave bass compensation for bass:

    16Hz +11.5
    18Hz +8.0
    20Hz +7.5
    22Hz +6.5
    25Hz +5.0
    28Hz +4.0
    31.5Hz +3.0
    36Hz +2.5
    40Hz +2.5
    45Hz +2.0
    50Hz +1.5
    56Hz +1.5
    63Hz +1.5
    71Hz +1.5
    80Hz +1.5
    89Hz +1.5
    100Hz +2.0
    111Hz +1.0
    125Hz +0.5
    142.5Hz +0.5
    160Hz -0.5


    Regards,
    Wayne A. Pflughaupt
     
  4. Nathan Stohler

    Nathan Stohler Second Unit

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    Thank you, Wayne.

    That's much different than the chart that I found on the web. For what I'm doing, I think I can ignore the corrections. I was doing some calibration last night, looking for peaks in valleys in the response of my speakers, so 1 or 2 dB here and there doesn't matter much to me.

    Also, my sub doesn't do a whole lot under 30 Hz, which seems to be where the major discrepancies are.

    I'll save this table away though for future use.

    Thanks again.
    --Nathan
     
  5. Wayne A. Pflughaupt

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    Forgot to mention (but maybe you already knew), you're supposed to add the posted values to the meter's reading.
     

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