Loudness levels of pro audio experts
What is a suitable loudness level for YouTube? Theory has it that -14 LUFS is ideal. But there may be problems. The pro audio experts all seem to think differently.
There are very few absolute rights or wrongs in audio, but the two ultimate 'must dos' are...
- Satisfy your client
- Please the market
So either you're working for a client who will be pleased to pay you if they like your work, and they'll ask you again.
Or you're selling directly into the market for audio, on CD, streaming, or even vinyl or cassette. If people like your work, they'll buy it, or play it more often. More streams of course equals more money for you!
So what about loudness? What's right? What's wrong? And what's going to please your client or market best?
The answer to this is seemingly simple -
- -14 LUFS for YouTube (used to be commonly stated as -13)
- -14 LUFS for Spotify
- -16 LUFS for Apple Music
- -23 LUFS for broadcast in Europe
- -24 LUFS for broadcast in the USA
But let's look at YouTube in more detail...
Yes, their loudness standard is -14 LUFS, but that only applies to video soundtracks that are at or above -14 LUFS. If the soundtrack is quieter than that, YouTube doesn't turn it up.
Let me set a benchmark for loudness - Metallica. I might have chosen a track from Death Magnetic, which is reputed to be the loudest album ever recorded. But I chose Enter Sandman because I think it is a more reasonable reference as a loud(ish) track.
So if I download the video file, bypassing YouTube's player and measure the loudness, using the Waves WLM Plus loudness meter, I get -8.3 LUFS. That is LOUD.
But if I capture the audio via the YouTube player I get - guess what - -14 LUFS. So by experiment we can see that -14 LUFS is YouTube's standard.
-14 LUFS is, by the way, still quite loud.
So this means that everyone is uploading their videos with the audio mixed to -14 LUFS, right?
Er, not quite right.
Let's consider Audio Masterclass videos...
Now I personally would like it to be that someone could watch a Metallica video playing back at -14 LUFS, then click through to an Audio Masterclass video at a similar loudness. If the Audio Masterclass video is quiet, a lot of people will think there's something wrong.
Fine. If I record a podcast and make a video version for YouTube, I can set the level to -14 LUFS. I'll have to use some limiting to get the level that high, but it will still sound OK. No problem.
But what if I want to make a video demonstrating compression on drums. Drums are very peaky and an uncompressed recording of drums could typically come in at -24 LUFS (I've just measured that as an example from a recording I made in Abbey Road Studio 3), even if the audio peaks at 0 dBFS.
So if I want to make a before-and-after demonstration of compression on drums, then the level can be no higher than -24 LUFS to avoid limiting the uncompressed audio and therefore invalidating the demonstration.
That's 10 dB below YouTube's standard level.
What do the experts do?
So, I thought, maybe I should take a look at what other people who comment on pro audio on YouTube do. They are experts whose opinions I respect, even if they sometimes differ from mine.
So without naming names, here are a few LUFS levels I measured, from different creators, bypassing the YouTube player and getting as close to the uploaded version as possible (in random order)...
-11.5 LUFS -16.8 LUFS -17.7 LUFS -16.6 LUFS -20.8 LUFS -16.2 LUFS -23.7 LUFS
And one of my own for comparison...
So we can see that this uninvited panel of audio experts, plus myself, has most definitely not come to a conclusion on what the right loudness level is.
The loudest at -11.5 LUFS is clearly too loud. Here's what the waveform looks like...
You can see how squared-off it is indicating intense limiting. The peak level is -0.8 dBFS.
Some of the other soundtracks are too low in level because they are below -14 LUFS, and also below both 0 dBFS and -2 dBTP (which is the true peak level specified for broadcast in the USA). They could have been louder at no detriment to audio quality.
Now my video at -29.1 LUFS is the quietest of all. This isn't something that I'm boasting about, it was essential. The video demonstrates EQ on kick drum and I didn't want to use limiting at all. The true peak level is -1.2 dBTP (which would be safe for broadcast in Europe, if not the USA) so apart from that odd 0.2 dB it could not have been any louder without limiting.
So do I have a conclusion?
Well yes on one point - the videos I've measured are popular and are clearly pleasing their audience despite being extremely varied in level. That demonstrates that what matters to the audience is the content, and they are quite capable of turning up or tuning down their monitor level control to suit their individual preferences.
On deciding a suitable level for YouTube? Well this is tricky. I could go for consistency, but certainly for the way I prefer to make demonstrations, which is not to use limiting to achieve more loudness, I would have to set all of my video soundtracks to a very low level.
Or I could set the level to suit the nature of the content - higher for speech-only, lower for demonstrations.
The level of this soundtrack by the way, is -14 LUFS.
If you would like to comment and share your opinion, please do. The issue of loudness is far from settled yet and the more debate we have the sooner we'll come to a solution.