Question about calibrating, db gets lower with 2 speakers playing

Discussion in 'Speakers' started by Johnny_M, Apr 19, 2004.

  1. Johnny_M

    Johnny_M Second Unit

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    I bought a Digital Video Essentials DVD and spent some time calibrating. This sure does help big time! the dvd player levels are no where near the same as when i calibrated with the internal test tones. but heres the odd thing thats happening...

    during the calibration it starts with the LEFT, so i set my volume until I reach 75db, no problem. Then the DVD goes to LEFT and CENTER speakers playing, the sound goes down about 2 - 3 db, then when it moves over to center only, it goes back to 75.


    this happens on a couple of the speakers and i cant figure out why. is it my receiver having a tough time with the load? when it plays all speakers at once it hits a steady 75db.

    I have a kenwood vr-7080 if that helps.

    Thanks for your input.


    Johnny
     
  2. Rick_Brown

    Rick_Brown Second Unit

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    One thing you can check is to be sure that all of your speakers are in phase with each other.
     
  3. Johnny_M

    Johnny_M Second Unit

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    how do you check that? is that just polarity? because those are the same. the speakers are also all yamaha, but the center speaker is 1 generation newer than the others. maybe that has something to do with it.


    Johnny
     
  4. Edward J M

    Edward J M Cinematographer

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    I would double check wire polarity at both the speaker and the AVR end. It really does sound like a phase issue.

    Oh, and don't calibrate the sub with DVE; the sub level is recorded about 13 dB too high, resulting in a very low calibration level. There is a big thread on the subject at HTF in this forum. Search for it under my screen name. Last post was probably 2-3 weeks ago.

    At a minimum compare the DVE sub level to another source, even your AVR test tones.

    Ed
     
  5. Johnny_M

    Johnny_M Second Unit

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    i noticed the sub level difference right away, so i calibrated that 1 by ear. ill check out that thread you mentioned, thanks!


    Johnny
     
  6. Rick_Brown

    Rick_Brown Second Unit

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    My favorite way to check polarity is easy if you can move your speakers around.

    Play a CD with fairly strong bass that is mixed dead-center. Place your left and right speakers facing each other. Reverse the speaker leads to ONE speaker. You should easily notice that one way has lots of bass and the other has very little. Go with the hookup that has the most bass. Usually this is consistent with how the terminals are labeled, but every once and while you find a speaker that is hooked up incorrectly internally.

    Now, you can use either L/R speaker to check the phase of your center and surround speakers in the same manner.

    This bass cancellation effect when out of phase is what we are thinking might be happening when your center speaker is on with the L or R speaker.
     

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