Audio Statistic Question

Cubase
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Statistics - Eternity
Statistics - Eternity452×624 31.2 KB

I’ve been trying for some time to understand what the “Cubase Statistics” panel says when you analyze an audio file. For this purpose, I downloaded the song “Eternity” from this link: https://www.youtube.com/watch?v=xAfNUoqQppU, converted it into a *.wav file (44.1 kHz) and analyzed it with Cubase. (See screenshot of the corresponding statistics panel). I understand most of what it says or it is irrelevant to me. However, there are still a few questions that I was unable to answer using YouTube tutorials or Steinberg Help:

  1. What is the Min. sample value?
  2. Why does the Min. sample value, in contrast to the Max. Sample Value at 0.00 dB show no minus sign in front of it?
  3. What does peak amplitude (L/R) mean?

On the subject of “Max. Sample Value” I found out the following. Please correct me if something is wrong:

The “Max. Sample Value” is the maximum value of the samples that have a distance of approx. 2 hundred-thousandths of a second (20 µs, 20 microseconds) at 44.1 kHz. Higher values can occur in between. These are called “True Peaks”. The “Max. True Peak Level” can be significantly higher than the Max. Sample Value due to errors in the AD/DA conversion or due to data reduction, e.g. when converting to MP3. Therefore, the “Max. True Peak Level” is particularly high when analyzing a *.wav file that was previously an MP3. The “Max. Sample Value” always has a minus sign (also - 0.00 dB) because it can never be above zero.

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My guess is that that’s not the case. What you describe is what I think #3, “peak amplitude” is. In some other cases I’ve seen it called “sample peak” or “absolute peak”. In other words the absolute value of the individual sample(s). You’re correct that True Peak is what happens if we interpolate (‘reconstruct a signal’) peak levels using multiple samples in a row.

I have no idea what max/min sample value refers to. I just tried testing it on a few files and it’s not really making sense to me. Fortunately everything we need is found elsewhere in that analysis so ‘whatever’…

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Statistics
Statistics1155×334 41.1 KB

Min. Sample Value is the level at the lowest point in the waveform.
Max. Sample Value is the level at the highest point in the waveform.
Peak Amplitude is the larger (closer to 0 dB) value of the two.
True Peak is the true peak value (EBU R-128 Inter-Sample Peak) at the largest amplitude.

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Thank you ASM! This is a great explanation. And thanks again for the great screenshot! I also see from your explanation that my assumptions regarding Max. Sample Value (and now also Min. Sample Value and Peak Amplitude) were correct.