LUFS, destructive editing?

[L3LL3]

Hi,

I just tested to change the LUFS value on one of my tracks and noticed that the result seems to be compressed/limited. Is this method destructive to the file, unlike ordinary normalization?

/LS

[SteveG_AudioMasters_]

Depends upon how you change the LUFS value. If you use the Diagnostics method, then it has a peak limiter built into it, which if activated will result in peak compression, yes.

[L3LL3]

Are there several, different ways to do this? I used the Match Loudness function and there is a box for True Peak Limiting, which is checked. For some reason it is grayed out though, but even if I could uncheck it I guess that the result would be clipped peaks, which is even more destructive?

[SteveG_AudioMasters_]

Yes - there are always several ways to achieve things like this! A big part of the issue here is that most people just regard LUFS as a number, and not consider what it is they are actually altering to hit it. First thing you have to remember is that a single LU is basically 1dB of level difference - so just raising or lowering the overall level of your file will alter the LUFS reading you get. And there are several different ways of measuring LUFS as well, of course. Rather than go through it all here, I suggest having a look at this introduction. You also have to bear in mind that there's a lot of  'Emporer's New Clothes' about this. The original idea was to try to get broadcast transmissions to be homogenised to the point where people didn't have to keep altering the volume between programmes and TV channels. Guess what? That doesn't work! But still, stations keep insisting that productions have to meet whatever LUFS standard they set, despite the fact that every station going feeds their entire output into an Orban Optimod before it hits the transmitter, and it's that that ultimately sorts out the levels, not you jumping though hoops to set a LUFS level on a programme you submit.

On the one hand, I'm a little jaundiced about this - I'll admit it. But on the other hand, there are still broadcasters who do not insist on LUFS levels, and have other methods they prefer to use. And when one of those broadcasters is the BBC, you have to take a bit of notice of what they say. So the other important document that I think everybody should read when it comes to LUFS, etc is this. Read it carefully...

[L3LL3]

But still, this method is used for mastering, right? If I understand things correctly the focus here is on the perceived loudness, i.e mid-range frequencies vs. than ultra-low and high sounds. At the same time, the transforming process is very quick. Wouldn't that bring out a different character to the sound (besides the pure loudness leveling) compared to traditional mastering with ordinary compressor work, normalization etc?

[SteveG_AudioMasters_]

I don't know of anybody who uses it for mastering, and that's certainly not what the original intention was. But in principle, if you compress (or more likely limit) the peaks of your sound to get the overall level higher, and alter the LUFS score then it won't alter the sound of the midrange that much, because it won't be touching it.

[L3LL3]

Hmm... Ar you saying that all it does (this LUPS modeling) is to compress/limit the waveform, nothing else?

[L3LL3]

*Dah! I hate not being able to edit my faulty posts here... LUPS LUFS 😬

And before... "i.e mid-range frequencies vs. than ultra-low and high sounds."

[SteveG_AudioMasters_]

You should have been able to edit a post - you can until somebody else has replied after it; then it's locked.

But yes - the only modifier available is peak limiting. Other than that, it's just level shifting. You can only turn off the limiter in the legacy Loudness settings, but there isn't really a lot of point in doing that! Like I said, the whole thing is only an academic exercise; as far as mastering is concerned I wouldn't ever use a LUFS number because I'm more concerned about what something sounds like - not what it measures like. And if Loudness Matching did anything major to the sound (like mid-range compression) then it would alter the overall effect anyway in a completely unpredictable way - and that would, for most people, be completely unacceptable.

The history to the whole thing is rather unfortunate in a way - it's all predicated on a failure to train broadcast sound operators properly, and an attempt to get around it by imposing numbers for them to meet. And what it does, of course, is make the situation worse, because they then get up to all sorts of fudges just to make the numbers work, without listening to the end result at all. And the ultimate upshot of this is that the most frequently used buttons on the remote (after the channel changer) are the volume controls...

So ultimately sound operators still have to learn to make a programme sound consistent, and there's a good chance that these programmes will fit the LUFS numbers easily - often it's just a minor level shift. But it's also possible to fudge the whole thing and get an apparent numbers fit by compromising short and long term measurements, and that's what causes the leap for the telly remote.

[L3LL3]

Steve!

I think that I get you now. This LUFS thing is just a kind of hoax, especially if all it does is to add a limiter to the track. Furthermore this function in Audition don't even seem to work very well. If I try to set the value 12, the number constantly changes to 6, no matter what I do!?!

I may just leave this thing behind and concentrate on my mastering instead. There is one thing that I don't really understand there... My creations are fairly loud, normalized to -0.1 dB with pretty good dynamics (and native LUPS values most often 10-12, witout even touching the loudness matching “knob”).

If I import commercial recordings in Audition I can (most times) see similar LUFS values to mine, but their waveforms often seem a bit quieter (normalization, somewhere between -1 and -3 dB). Still they sound louder in my speakers. Both mine and the commercial songs have good dynamic waveforms. What’s the trick?

PS/ I wonder where I can find that edit button, if there is one? 🙂

[L3LL3]

No options to edit (if I don't look at the wrong place)

 

[SteveG_AudioMasters_]

I think you should find the edit button under 'More'. (unless they've been playing about with the format again - quite possible...)

To get tracks to sound 'louder' without hitting 0dB, generally you'd employ multiband compression. If you look at the 'Broadcast' preset, and listen to the effect it has, you'll get the basic idea.