Difference True Peak values in Loudness Meter and Supervision

After analysing the statistics of a rendered mixdown, I noticed the true peak was at -5dBTP, while my True Peak limiter was set at -1dbTP and Supervision also indicated that value (-1db). When now looking at the Loudness meter in the output channel I indeed see it shows -5dBTP. What is the difference or what am I doing wrong ? FYI I do render at 16 bit - 44 kHz (while recordings is at 24 bit - 96 kHz).

Hi

I found the issue. Super Vision does not always reset values.
Still there is a slight difference in dB (0.2). Can live with that.

Hi @elgwiedo Do you observe a difference too if you use the Sample Accurate mode of SuperVision?

See Maximum Audio Performance/Sample-Accurate Display in:

I am experiencing a major difference between True Peak values as between VU metering in SuperVision and Loudness meter in Control Room. I have SuperVision inserted in first slot on my Master output track, pre-fader. I previously used the just the VU meters in Waves CLA Mixdown with every other feature bypassed, instead of Supervision. Now, I just ignore the Supervision numerical True Peak values–which are just confusing me, and use just the needle metering. I have been able to configure SuperVision VU meters so the needle moves the same as the one in Waves. Here are screenshots of the SuperVision VU meters, the Supervision settings for that VU meter, and the Loudness meter in Control Room–all metering the same audio tracks.


SuperVision Settings

Notice that under the VU meters, it shows True Peak as +10.54 or +10.39 dB, and the Loudness meter shows True Peak as -7.32 dBs. In general, the Loudness meter very accurately displays the True Peak and other data. In contrast, the True Peak values under the VU meters are drastically off, and dramatically different from those in Loudness meter.

What am I missing here, or what am I doing wrong?

Maximum Audio Performance feature (on or off) does not affect this situation significantly.

The VU meter scale doesn’t even go as high as +10 dBs, and the overload lights never turn on. In my experience, True Peak values any higher than 0 should cause all sorts of distortion and other audible issues with audio–especially on mixdown to 16 bit. Yet, when I follow the Loudness meter (and ignore the True Peak values in VU meter) to set my mixing levels, I get great results. I think this may have something to do with the offset value of -18 dBFS in Supervision (i.e., True Peak value in Loudness meter minus 18). In any event, I find the VU needle-style meters a very useful reference for gain staging, especially because I use several analog-style plugins. I hope someone can explain why the True Peak readings in Supervision are so far off compared to those in Loudness meter. What can I do to have the True Peak values read the same as between the two meter types/locations? Thanks in advance for any help or information.

I’m too tired to do the exact math, but if your VU meter is offset by -18 then just looking at the numbers that should imply why there’s a discrepancy. In other words the difference between the numbers 10.5 and 18 is 7.5… roughly. If I’d had more coffee I’d think harder.

Experiment with the VU calibration to see how the numbers change. Also try changing the scale and/or meter mode. I recall there’s some difference there. A thread about it some time ago.

I would just skip the VU meter completely and focus on loudness metering (for True Peak).

Hi Matthias. Thanks very much for your input. I suspect the numerical True Peak readings in VU meter, within SuperVision have a bug. I previously tried changing every setting parameter available for VU meters. Nothing results in a numerical True Peak value that jibes with the Loudness True Peak reading. The settings I am using are the only ones that make the VU meter needle behave up to expectation. I will continue to ignore the VU meter numerical True Peak values until either someone suggests how I can correct it, or Steinberg fixes it. Even if the “offset” of -18 dbfs does explain the discrepancy (e.g., the True Peak on the Loudness meter analyzed a longer portion of the audio since I reset it, so the math in my photos does not add up to exactly 18), it makes no sense for Cubase to display internally inconsistent True Peak values. By that, I mean the numeric dBs shown under the VU meter do not align with the scale on the needle part of the VU meter above it, nor do they align with the Loudness metering.

I agree; if the offset also offsets the numerical readout for peaks they shouldn’t be called “True Peak” but something else.

Hello everyone,
The TruePeak displayed on the Label in the Level module is indeed using the dB Offset parameter. So if that offset is enabled for example with a scale such as DIN or the standard VU scale, then yes the TruePeak values will actually be displayed with an offset.
If you think this should not be the case, it can be reported as a bug?
Also keep in mind that the Level/VU modules display the Channel TruePeak, while the Loudness display the Global TruePeak.
Thanks again for your valuable inputs!

1 Like