3 Replies Latest reply on Dec 18, 2008 2:24 PM by Dag Norum

    Audio levels different from camera to Premiere Pro

    Webshark2000 Level 1
      Why is it that the audio levels on the camera can show the subject peaking right above -10dB, but when I bring the clips into Premiere, they are below -12dB and I always have to boost them?

      Just to test this, I cranked up the volume on our camera's inputs to the point where it was clipping. When I took this clip into Premiere it still wasn't hitting 0dB. It was peaking into the yellow, even though the clip was completely distorted because of the clipping coming into the camera.

      Is there a way to calibrate either Premiere Pro or our camera so that they match, so when you are peaking at -6dB on the camera, it's the same in Premiere Pro?

      I know the solution probably involves a tone generator being used with the camera, which we have, but I'm not exactly sure what to do.
        • 1. Re: Audio levels different from camera to Premiere Pro
          shooternz Level 6
          I am no sound guy but ...

          My recordist usually does a set up using a tone generator.. 1000khz tone at -12db (I think). That is because there is an increment on the camera audio levels monitor at -12db . This coincides with PremPro level meters.

          What camera are you using? Maybe an issue in your camera input stages.
          • 2. Re: Audio levels different from camera to Premiere Pro
            Webshark2000 Level 1
            We use a Sony HVR-V1U, a Panasonic DVX-100B and a JVC GY-DV500. The problem is similar on all of them, although the gap is smaller on the DVX-100.
            • 3. Re: Audio levels different from camera to Premiere Pro
              Dag Norum Level 2
              >I cranked up the volume on our camera's inputs to the point where it was clipping. When I took this clip into Premiere it still wasn't hitting 0dB. It was peaking into the yellow, even though the clip was completely distorted because of the clipping coming into the camera.

              What I think is you have run into is definitions of the dB. One has dBm and dBV in the electrical world, among a lot of others (for example sound pressure/power and different types like dBA, dBC, and so on within sound levels).

              Anyway, to make this not to be a too deep lesson in deciBel (dB), it seem like your cameras define 0dB to be something different than what Premiere defines it to be. The dB presentation (what the display shows) is a logarithmic number depending on a reference level, meaning in this case, if the voltage (sound turned into electricity) hits for example 1 Vrms then we'll call that 0dB (which is probably what Premiere does, and maybe your camera uses 0,775 Vrms as 0dB reference).

              Clear as mud so far, right, just wait for the following. Just kidding, but look up decibel in google, and you'll find a pretty complex world.

              Bottom line:
              I don't think you can get the dB levels in Premiere and your cameras to match, unless your cameras have a setting that defines the 0dB level. The best you can do, in my opinion, is to learn the difference and go from there as you have ("I always have to boost them"). But, also remember that if you do some audio stuff in Premiere that you want to record back onto tape, you'll have to go the other way, lessen the audio level.

              Reference levels made by a tone generator is a fine way to learn the differences.

              Dag

              EDIT: Allthough it probably is a definition question, just never let your camera go over 0dB. As you have noticed, it will be distorted sound. The electric circuits on your camera won't handle over 0dB well.