First it was Spotify, then Apple, then YouTube – now TIDAL are implementing loudness management, or “normalisation”, to give a better user experience, stopping us from being “blasted” by level changes between songs.
If you’re a regular reader you’ll know why this is a big deal already – if not, click here to get up to speed quickly. In this post I’ll just cover what’s interesting and different about TIDAL’s loudness management system. As always, the devil is in the details.
TIDAL uses LUFS
Finally ! The ITU’s international standard method of measuring loudness, “Loudness Units Full Scale”, or LUFS, has been agreed for years, but none of the music streaming platforms have actually been using it – until now.
TIDAL are using LUFS, and have released clear information about their chosen playback levels. Over AirPlay, normalisation will be at -18 LUFS, whereas on mobile devices and broswers, all music will be initially be played back at an integrated loudness of -14 LUFS.
This is great news, since in my experience the LUFS meaurement is easily the most reliable way of measuring loudness, and most closely matches what my ears tell me.
Sadly TIDAL’s chosen level of -14 LUFS is still louder than the recommended -16 LUFS maximum specified in the AES guidelines for streaming loudness that I helped draft, but it’s a little better than YouTube’s estimated -13 LUFS level, and far better than Spotify’s level of approximately -11 LUFS.
So far, so good. But…
Quiet songs WON’T be turned up
This is an unexpected curve-ball. All the loudness normalisation services turn louder songs down to their reference level, to stop you being blasted by a song at very high level following just after a quieter one – but they also turn quieter songs up, too – provided it doesn’t cause clipping, a least. TIDAL doesn’t do that.
At first sight this doesn’t seem like a huge deal – most songs are mastered with a higher integrated loudness than -14 LUFS these days anyway, so are unlikely to need turning up.
There are cases where you need to be careful, though – for example if you’re used to supplying music for use in broadcast, which requires you to maintain an overall -23 LUFS integrated loudness. On the other services I’ve tested, songs like this will be turned up, provided it doesn’t cause clipping (although Spotify uses a limiter.) TIDAL won’t do that, so music supplied at a broadcast level like this would sound very quiet in comparison to everything else.
Having said that, since one of TIDAL’s biggest selling-points is CD-quality streaming, this may not be such a big deal – whereas YouTube recieves lots of video content which may be already optimised for broadcast, most TIDAL material will come from a CD master or higher quality file, which is likely to be at a higher level already.
Lower-level older releases may be affected by this detail too, though. And if you choose to deliberately master your music at a lower level, it will sound quieter than the loudest material on the servcie – but if you make that choice, the chances are that’s exactly how you’d like it.
Normalisation can be disabled, but not in browsers
Finally, TIDAL allows users to toggle normalisation on and off in the settings – on iOS and Android, at any rate. In browsers the option seems to be permanently on – just as with YouTube and Pandora.
TIDAL’s implementation of loudness normalisation can only be a good thing. It gives us a better user-experience, and it allows artists and engineers to master their music with the dynamics that work best, without having to worry about “competing” in the loudness war.
And their choice to use the LUFS measurement system is very wise, in my opinion – hopefully other services will follow suit soon. Their choice of yet another different reference level is confusing for people who want to optimise dynamics for streaming, though – which service do you prioritise ? Do you upload different masters for each service? But hopefully in future all streaming services will adopt the AES recommendation of -16 LUFS max – if you’d like to encourage them, please click here to sign our petition !
And in the meantime, you can measure the peak to loudness ratio (PLR) of your music to assess how it’s loudness will be treated online with any LUFS loudness meter – or my Dynameter plugin, which offers presets to help with exactly that.
Coda: But what about SoundCloud ?
More and more people have been asking me recently about loudness normalisation on SoundCloud, which is where many of you release your music.
The bad news is – there’s no loudness normalisation at all there, yet.
I’ve been in contact with SoundCloud’s support team, who have said I can quote them as saying that normalisation is “on the list”. It’s not at the top, right now – but that may change, especially as SoundCloud is being bought by Spotify. Let’s just hope that when the two services merge, they implement not only loudness management on SoundCloud, but the AES’s recomended maximum reference level of -16 LUFS, too.