SPL Calbration w/ THX Optimizer instead of Avia or VE?

Discussion in 'Home Theater Projects' started by Geoff S, Jun 14, 2003.

  1. Geoff S

    Geoff S Stunt Coordinator

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    Would saving money on buying a Avia, or Video Essentials DVD be OK, If I just use the THX Optimizer's 75dB Pink Noise to calibrate all my speaker levels with a Analog SPL Meter?

    Yay, or Nay?
     
  2. Bill Kane

    Bill Kane Screenwriter

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    That soundtrack calibration is supposed to be good for that disc only, that is, optimized for that specific DVD sound mix.

    Go for the $17 Sound&Vision Tune-Up disk, cheaper than Avia but produced by the same company, at amazon.com Here or maybe thru barnes&noble.
     
  3. Geoff S

    Geoff S Stunt Coordinator

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    Hmmm. but wouldn't 75 dB be 75 dB regardless? How do they measure this?

    Unfortuantely I only have $40 right now for a Analog SPL meter, so any other Calibration discs will have to wait.

    I will do a combo of the THX Optimode on my T2:UE and my receiver's own test tones to find a balance before I get another calibration disc.
     
  4. Bill Kane

    Bill Kane Screenwriter

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    geoff,

    experimenting with yr system and learning more about various ways certainly is a fun idea -- this is a hobby, right?

    here's a little read that suggests why THX Optimode may not be spot-on for whole system audio. I cant speak about the video portion. Click
     
  5. Geoff S

    Geoff S Stunt Coordinator

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    OK, I just tried it.

    Speaker levels sound much more balanced out... however reference volume sounds way to quiet. Here's what I did:

    (quick system specs: Denon 4802, BA VR-950 mains, BA VR-12 center, BA VR-10 EX, Def. Tech BP1X surrs. I did not calibrate the sub)

    I kept the mains at 0db and adjusted the volume till I hit 75dB on the meter. The center needed to come about -5dB lower, the surrounds 1db up, and the EX -2dB. The reference volume came out to be -12 with keeping the mains at 0.

    Bill, I read the link you posted and it states that the THX Pink noise in some cases can be as much as 10 dB off, and it sounds at least 5-10 dB off on mine. Thank you so much for this info. So for now I'll keep the levels the same, and run the volume around -07 to as low as -02 on my Denon to try to get close to what it should be.

    I will invest in a better calibration disc, either VE or the Sound & Vision you mentioned next week. Thanks!
     

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