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Old 06-10-2016, 03:11 PM   #29
plush2
Human being with feelings
 
Join Date: May 2006
Location: Saskatoon, Canada
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So I did a bit more digging. The surround channels are measuring -3dB on the VisLM meter compared to the DPMeter. This is a theatre audio thing where they are attempting to compensate for the phenomena that humans are approximately 3dB more sensitive to sounds from behind.

It also appears the VisLM meter integrates over 3 seconds as opposed to the DPMeter 400 ms. Also the VisLM meter gradually rises to that integration value whereas the DPMeter waits and then jumps to it's first value after 3 seconds. This is probably not important but I mention it just to be thorough.

With these two adjustments made the movement of the meters seems to correlate very well but the DPMeter still reads approximately -0.7 to -0.8 dB LEQ(m).

In short, lower the volume -3dB in the RS and Ls channels respectively, increase RMS window to 3000 MS and raise the gain either 0.7 or 0.8 and the DPMeter (as far as I can tell) will be within .0 dB LEQ(m) of the VisLM meter.

That 0.8 dB gain setting certainly wouldn't inspire confidence but it works. I'm hoping you will see some tweak in the algorithm that could explain the difference.
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