Confused about different LUFS results

[J. Smith]

Hello all!

I have trouble understanding why FabFilter Pro-L 2, iZotope RX 8 and Studio One's Project Page and Studio One's Audio Batch Converter give a different LUFS reading for the same file.

Pro-L 2 and Studio One's Project Page give -17 LUFS.
iZotope RX and Audio Batch Converter give -20 LUFS.

What is different in the way they measure things? All measurements are integrated measurements.

[J. Smith]

Nevermind! Now I know about mono LUFS and stereo LUFS

[kingozrecords]

Ok, but also keep in mind that there's furthermore different specifications. One is 2014 and the other is 2016, but 2016 is rarely used because it also uses oversampling and is harder to construct. However, if you're to find out that the commercial company indeed endorses and uses ebu 2016, you can ultimately make your music 1 LU louder, because of increased tolerance due to more accurate tp. At any rate, this is not suggesting that you could make it louder, but instead it gives you a wider berth for the margin of error that likely will occur.

[J. Smith]

Thanks king! Thankfully the client gives me a margin of 3 LU, so as long as I'm in that range everything's well.

[Hermetech Mastering]

LUFS uses an oversampled meter, which in a sense "guesses" what the reconstructed analogue waveform will actually be. There are different implementations of oversampling which will give slightly different results. I never worry if they are not exactly the same. I have used RME Digicheck, Youlean, DMG, RX and Acoustica LUFS meters at different times. But they also shouldn't be too far off, should be within around 0.2dB of each other.