Sound & Vision Calibration Disc Question, Help Please!

Discussion in 'Archived Threads 2001-2004' started by Shaun, May 21, 2002.

  1. Shaun

    Shaun Second Unit

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    I finally went out and bought a calibration disc (Sound & Vision Home Theater Tune-Up) after years of just using my SPL Meter with the receiver's internal test tones. My concern is with the audio calibration. What reference level should I use when calibrating speakers and subwoofer? Is it 75db or 85db? I've done a search on the forum and couldn't find any answers. My guess would be 85db since it's made from the same people who made the Avia disc.
     
  2. Bill Kane

    Bill Kane Screenwriter

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    Shaun/Shawn,
    The S&V disc is not specific since it's not intended for anal geek tweakers.[​IMG] It says "over 70dB." Your guess @ 85dB in all probability is right.
    Even the Avia disc says 75dB calibration level is fine for most living rooms. Technically, Avia or S&V ref lvl of 85dB incorporates a 30dB calibration offset so we dont blast our ears setting up. The 85dB CALIBRATION level meets Dolby Labs "REFERENCE LEVEL" standard of reproducing DVD soundtrack PEAKS of 105dB and 115dB for the LFE, designed for movie theaters originally.
    After calibrating to this Dolby reference level, however, many of us don't play this loud -- more like 10 to 15dB less volume for more comfortable listening.
    So you can just as well calibrate to 75dB and in playback not turn the volume down as much.
    I've done it at both levels and I have both Avia and S&V. Sometimes there is a difference in balancing a pre/pro & ext. amp setup vs. receiver only for the optimum volume control setting in one's particular system.
     
  3. Paul_Fisher

    Paul_Fisher Screenwriter

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    The Sound & Vision disc says you should set the SPL meter to 70db. I'm not really sure what this means, but thats what it says.
     
  4. Bob McElfresh

    Bob McElfresh Producer

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    The Radio Shack analog meter has numbers & lines for 70/80 db. This makes it real easy to see when you are dead on. Trying to set to 75 db - you have to judge if the needle is between the hash-marks on the meter.

    Try this: Calibrate at 80 db. Then use the test-tone and reduce the volume to 70 db. Are all the speakers still producing the same volume? They should be darn close.
     
  5. Bob McElfresh

    Bob McElfresh Producer

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    PS: Use a laser-pointer on your speakers to "see" where they are pointing with respect to your central listening position. You may be suprised at how far off they are if you have just done this by the eyeball method.

    Just hold the laser pen against the side of the speaker cabinent.

    Your speaker will throw a sound pattern like the light from a D-cell flashlight - very bright/loud directly in the middle, and a sudden drop off. A small angle change in your speaker can have a large volume difference at your seat.

    So adjust the angle/position of your speakers first. Then use the test-tones to level adjust.
     
  6. Bill Kane

    Bill Kane Screenwriter

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    C'mon Paul, let's not shoot from memory. Under "How to Use A Sound Level Meter" the narration says set the meter to the 70dB range:

     
  7. ThomasL

    ThomasL Supporting Actor

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    Shawn, the most important thing is balancing your speakers. What db level you use to do this calibration level isn't as important as actually getting things balanced. I use 60db since that is actually where I listen to movies at most of the time. Many people like to do 75 or 85db simply to know where on their volume knob reference level is. I've turned the master volume up to 70db when calibrating and the speakers are still balanced with the same settings as they are at 60db.

    hope this helps,

    --tom
     

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