Sub calibration...where to measure?

Discussion in 'Speakers' started by Daniel T., May 4, 2003.

  1. Daniel T.

    Daniel T. Agent

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    Been diggin around, and have the steps down to get a decent reference level, but I don't know where to take the SPL readings. I layed the meter in front of the sub and got wildly varying numbers depending on how close the meter was. Up close 90, where I sit won't even register(less than 50 I'd guess). I'm using pink noise from the DVD player, do I need a tone or something?
     
  2. EricSm

    EricSm Stunt Coordinator

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    Ideally, you would measure the test tone from the ideal sitting position in your room. Hold the meter steady or tripod mount it where your ears would be. You can use your receivers internal test tones provided it has them for the subwoofer. Some dvd's(Toy Story series for example) have a thx optimizer that has test tones on the dvd that you can use. There are quite a number that used a dedicated calibration disk like Sound and Vision's Guide to Home Theater or Avia. Both of those disks have excellent calibration tools- Avia's being a bit more extensive while Sound and Vision offers 6.1 system calibration. Either one works fine.

    The whole goal in calibrating speaker levels is to get all the of channels producing the same signal level so that one channel does not overly dominate the sound field. Further, it's a great way to recreate in your home theater the sound the way the film's sound editor's intended it to be. Having said that, quite a few people find that setting their sub woofer level a few db hot(higher than the other channels) provides more of an visceral impact.

    Hope that helps.

    -eric
     
  3. Daniel T.

    Daniel T. Agent

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    Hmm, seems I was vague. I have the mains/center/surrounds calibrated. But the sub does not show up on the SPL meter with the internal pink noise, I know its *close*, because during movies the whole dang house shakes, if I had it boosted to 75db at "my ear" it would be entirely too loud. I'm guessing I need a 30hz tone or something.
     
  4. Edward J M

    Edward J M Cinematographer

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    Daniel:

    If your SPL meter is registering the test tones for the surrounds, but is reading much lower (or not at all) for the subwoofer, I suspect it might be set to A-Weighted. If this is true, switch it to C-Weighted Slow and see if it starts to register the bass rumble test tone.

    Regards,

    Ed
     

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