How should I interpret this "crest" meter reading?

[Ddavis]

Mloudnessanalyzer1.JPG

Hi, I don't understand the crest meter reading that is attached. How can I have a -100 reading and how can it be all green, all red and all black at the same time? Also, the range reading is slightly in the red and your documentation says that red means it "needs attention" but what kind of attention? Thanks! Dave

[DarkStar]

I get that when then is a silent part of the audio (or I pause playback in the host). It should go back to 0 dB after a few seconds. And it looks like the bars are drawn from the right-hand side leftwards, so, red, green, then black (or white, depending on the background). I do not remember if it was always like that. Perhaps that is a bug, and the bars should be drawn from the left-hand side - that way we will only see the red area when the crest is low (right now we always see it).

If the Crest is in the red then the ratio of RMS level to peak level is too high. This oculd be down to over-compression or limiting or both. Ease back on them to keep more dynamic range. Aim to see green most times.

Crest meter shows the output crest factor (calculated as RMS divided by peak level), which essentially indicates how extreme the peaks are in the output waveform. The lower the value is, the more peaks there are in the output, the more dynamic it is. If the value reaches 0dB, then the output is over-compressed and flattened and you should consider going easier on the compressor and limiter.

The range from 0dB to -6dB is red and you should prevent your master output from remaining in this range as that would mean it is extremely over-processed. The green range from -6dB to -10dB is the range most that recordings are in, usually jumping below the -10dB.

Please note that other (developers) calculate the crest factor as the peak level of the waveform divided by the RMS value of the waveform, and the higher the value, the more peaks there are in the output, the more dynamic it is.

[Ddavis]

Dark Star: Yes, I read that bit about how it "should" work but it left me confused. But your comment that you get that reading for silence helps a lot. I was thinking that, like Range and Integrated, the reading for Crest was the overall reading for a clip, but I guess that's wrong, so that helps a bit, too. I guess one has to watch this meter and see where the overcompressed bits are as the clip plays in real time. I'm not too worried as I don't really use much compression and the PLR meter reading is fairly high which indicates good range and not overcompressed signals.

As for the red bars in the Range reading, if I take measures to eliminate them, then my Integrated reading gets out of limits. For PBS, integrated seems more important than Range, so I'm hoping there's enough green there and not too much red to bother with.

Thanks!!

[DarkStar]

While I do not understand it fully ...

Crest is a dynamic measure; it changes throughout the song. Here is a seasonal view in the TIme-graph; the Crest are the icicles.

[Ddavis]

Thanks DarkStar. That's helpful. Yeah, I was mis-reading it as an overall reading not dynamic. Makes sense.