Different loudness readings with different meters

[Manne Kjellander]

Hi!

I have two issues that are kind of related.

First I'm trying to measure the loudness and true peak of a 5.1 feature film mix (for compliance with EBU r128). I get the following values from three different meters:

NUGEN LMCorrect -23.3 LUFS -1.2 TP
Youlean Loudness Teater 2 -23.1 LUFS -0.8 TP
Avid ProLimiter Loudness Analyzer -22.7 LUFS -1.5 TP

How can this be? Which one is correct?

The second issue is that I use a Pro Limiter on this mix. It's at -1.5 (both threshold and ceiling). Still two of the meters shows peaks above that. Makes sense that Avids meter shows -1.5, just as the limiter is set. However it sounds unlikely that NUGEN would show .3 db off!? Don't know about Youlean but from my understanding NUGEN is a widely used and respected brand.

Very confused here. Any help would be very appreciated!

/Manne

[henningaround]

A while ago I used the Flux Elexir as TP Limiter. I had to set it to a threshold of -3,8 to never have peaks higher than -3dB. Since then I never had the feeling that I can trust a software limiter completely. I always set a threshold lower even if I now use ProLimiter or NuGen ISL.

[Bob Olhsson]

There is no "precisely correct" meter because of the wide variation in program material and looseness in the R-128 spec. It's a wide world of "sort of." For that reason, it's a bad idea to really push the limits.

[Manne Kjellander]

Thanks for informing me! Thats the conclusion I reached from digging into it as well. For some reason I was under the impression that the r128 standard was absolutely unambiguous, but it's not. Even the algorithm for calculating TP is up for debate as Julijan Nikolic of Youlean Kindly informed me. It's good to learn!