AVIA Calibration - What's the deal with the LFE sweep?

Discussion in 'Archived Threads 2001-2004' started by Willem Vos, Feb 14, 2003.

  1. Willem Vos

    Willem Vos Stunt Coordinator

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    Hi,

    I've got a similar thread running at speakers & subwoofers, but I'm not getting much response there...
    I recently got the AVIA Calibration disc, and have been running the LFE-sweep 100Hz to 20Hz. Is it normal for it to slope up from 100Hz to 65Hz? I'm measuring zilch (well, a little) response from the sub from 100hz to 70hz

    I know crossovers slope at the crossover points, and are not solid boundaries.

    So I set my crossover to 120Hz and my speakers to small. My mains are not participating when running the sweep, which is logical.

    But this would mean the full 120-20 LFE bandwith would be sent to the sub, but funnily enough this is not the case. What gives?
     
  2. Dave Poehlman

    Dave Poehlman Producer

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  3. Willem Vos

    Willem Vos Stunt Coordinator

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    Thanks for the reply Dave.
    Yes, I am using the crossover on the receiver. The crossover on the sub is disabled. I'm all out of ideas...
     
  4. I would burn a test sweep from 10-100hz on an audio track. Then hook up the sub amp to the L/R output on you reciever and make sure that they mains are set to LARGE (IE crossover in the amp is dissabled).

    If you do this and the sub is still somewhat attinuated in the 100-70hz region, then the XO is NOT dissabled on the sub amp and you are hearing almost zilch because you sum your 2nd order xos to a 4rth order (-24db/octave).

    hope I was clear enough

    good luck!
     
  5. Willem Vos

    Willem Vos Stunt Coordinator

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    Thanks, Anthony.

    That would be a sure fire way to test the existence of crossover. I'll try it out.
     
  6. Pete Mazz

    Pete Mazz Supporting Actor

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  7. Willem Vos

    Willem Vos Stunt Coordinator

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  8. just turn the LFE off and let the LFE get set to the mains which are set to large.
     
  9. Pete Mazz

    Pete Mazz Supporting Actor

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  10. Willem Vos

    Willem Vos Stunt Coordinator

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  11. Willem Vos

    Willem Vos Stunt Coordinator

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  12. Pete Mazz

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  13. Willem Vos

    Willem Vos Stunt Coordinator

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  14. Brian Bunge

    Brian Bunge Producer

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  15. Willem Vos

    Willem Vos Stunt Coordinator

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    Thanks, Brian. That's good to know.
     

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