Loudness norms (and why you should follow the rules too!)

Our loudness perception is relative. Some sounds we think sound loud, actually don’t sound loud and visa versa.

Our ears are most sensitive in the midrange, so when lows or highs are peaking we don’t perceive this as loud, but when something in the midrange is peaking we do perceive it as loud. Therefore when we apply saturation to a signal, adding overtones in the midrange mostly, we tend to perceive that sound as louder. Overdriving 808 kickdrums for example is a populair technique these days. It makes us believe that kickdrum sounds louder, but only additional harmonics are added. The peak is not louder. It’s a trick that is also useful because it “translates” the clean sine wave 808 kickdrum sound to devices which are not able to reproduce the super lows. Overdriving a 808 kickdrum makes it more midrangy sounding without loosing any of its booooooom. Even on a smartphone you will be able to hear the kickdrum because of the added midrange.

And the sound is actually indeed louder when we add transients to a signal using saturation. Those additional frequencies make the overall RMS/LUFS values go up. The peak frequencies will stay the same when overdriving a signal (added overtones are not peaks). So the RMS/LUFS is going up and the sound will be louder. Saturation causes the signal to compress (making RMS/LUFS values go up) but without using a compressor. This is the magic of saturation. Adding overtones, adding colors to a signal. Playing Vincent Van Gogh for sound. LOVE it!

But be warned! When RMS/LUFS goes up this means the sound will be less dynamic. So using saturation will always be a compromise between added loudness and loosing some of the dynamics. Music needs dynamics. And it needs compression. When you overdo it the sound will be too much distorted, too much compressed, or simply put: boring sounding.

Loudness war

For many years there was this thing called The Loudness War. Most mastering engineers where pushing the tracks into a brickwall (read: hard clipping using limiters, creating ODD harmonics). Some still do. That sounded awful because of the lack of dynamics and the hard clipping sound they created using brickwall limiting. Hard clipping can be useful though, on bassdrums for example. The 808 for example with its sine wave tone doesn’t have much overtones. When we overdrive this with hard clipping the sine tone will turn into a square wave tone. So we’re tweaking the 808 oscillator in a funky way by overdriving it :)

During the loudness war rule number one was: there are no rules. So everyone was trying to compete, to sound louder than someone else’s track (read: getting the loudest RMS, clipping the master like crazy!) using brickwall limiters.

I f#cking hated that sound!

Follow the rules!

Late 2010 EBU published the first version of its Loudness Recommendation EBU R128. Soon many European broadcasters started using that norm. Basically EBU R 128 recommends to normalize audio at -23 LUFS (from beginning to end). LUFS is like RMS. This means that the average loudness of a track should be at -23 LUFS when you mean to broadcast it on radio.

It’s great to have a super useful norm for radio programs. It makes creating/mixing/enginering documentaries an easy task. Balancing the voices against other sounds is just a matter of listening and keeping an eye on the EBU R128 plugin you’re using. Super easy and convenient.

War is over! War is over!

What about streaming?

Unfortunately iTunes Music, YouTube and Spotify don’t follow the same EBU R 128 dynamic rules. In fact they have created their own loudness rules:

iTunes Music : - 16 LUFS

YouTube: - 13 LUFS

Spotify: - 12 LUFS

This means that when you mix your track based on the iTunes rules at -16 LUFS, this track will sound more dynamic in Spotify than one which is mixed based on the -12 LUFS norm. More dynamic but also: less loud.

But the other way around is even worse. A track that is mixed based on the Spotify -12 LUFS norm will be lowered in volume when played in iTunes. So a track mastered for Spotify will actually sound a little duller and softer in volume when played back in iTunes Music. What the fuck? Yes, what the fuck :)

So now what? What rules should we follow then? That’s a tough question to answer. If you mix your track based on the EBU R 128 norm your track will sound mind blowing fantastic when it is played on the radio. But on Spotify your track will sound less loud than the norm. It will sound more dynamic though.

Mixing very dynamically, using for example the EBU R 128 norm, will make your track sound super dynamic (read: not boring) on any of the streaming services. But it will also make your track sound a little less loud compared to tracks which are following the higher LUFS values.

Popmusic needs compression, so the question these days still is: how much? Spotify says -12 LUFS, but maybe the more dynamic norm of Itunes at -16 LUFS is better?

Keep in mind that most streaming upload services like Distrokid will ask you for just one file to be uploaded to all the services. So creating separated mixes for like iTunes and Spotify is not at all convenient.

What to choose?

A track that is mixed/mastered at EBU R 128 will sound louder on the radio than a track that was mixed/mastered based on any of the norms the above mentioned streaming services are using. But when played back on one of the streaming services such a track will sound a little too soft, less compact and compressed, less loud.

EBU R 128 is a fantastic norm for radio. It’s great for balancing voices, sound effects and music. BUT I don’t think it is the ultimate norm for music. If we all would follow the norm, surely it would be, but since popmusic is compressed (read: high RMS/LUFS) it would be tricky to ignore the rules modern streaming services are using.

So therefore I come to this conclusion: mix/master your music based on the iTunes norm of -16 LUFS. It is in my opinion the best compromise between dynamics and compression for modern music.

P.S. what loudness norm is SoundCloud using? Deezer? Tidal? Google Play? I would love to find out!

The Mastering Show podcast recently did an interesting episode on loudness. How to make something sound loud?


Originally published at Melodiefabriek.