Understanding the LUFS metering system

In this digital age, there are so many ways that we can measure the level of audio. For many years, RMS averaging has been the scale of choice for mastering engineers to determine final loudness. However, since 2006 the LUFS metering (Loudness Units Full Scale) system has emerged and broadcasting services are beginning to make a stand on loudness.

So, what is LUFS metering?

LUFS is a measurement of loudness units designed in line with ITU-R BS.1770 recommendation about the loudness and true peak level of audio. The concept of a loudness unit is identical to a decibel. However, the loudness units measurement system is weighted to the real perception of audio rather than just the electrical signal. Ultimately, this has far more real world carry over. It makes the balancing of multiple audio sources far more manageable because you’re metering the final product and not the electrical source of varying projects.

Ok, I get it, but what do we need it for?

How often do you find yourself browsing through your eclectic iTunes library or rolling through the suggested videos on YouTube only to have to continually adjust your speakers because the next song is way too loud or way too quiet? Ok, perhaps not all the time but I certainly find this to be a regular occurrence with myself. By complying with the LUFS metering system and its standards, we can remove the doubt and ensure that all music plays back at a consistent level. This creates an enjoyable experience for the listener. Let’s face it, the audience is always the most important person to cater for.

I’m sold, so what level should you work to?

This is an interesting question that still sees quite a lot of discussion online. However, the important thing to consider is where your final product is going. Thinking about getting your music on iTunes radio/store? iTunes operates a guideline of -18LUFS and -1dBTP. Perhaps you’re more interested in Spotify? Their recently adjusted guidelines specify a level of -16LUFS.

I get a lot of clients who often wish for a little more loudness when I send through their master files. However, I generally find that a top limit of -14 LUFS is acceptable. The most important issue to consider is where your music is going. Mastered your mix to -8LUFS? When you upload it to Spotify all you’ll have achieved is removing dynamic from your track which results in a pretty quiet song once Spotify’s algorithms do their job. Over limiting is just as bad as over compressing.

So, now you’re completely sold on the idea (thank me later), what options have you got available? Thankfully, the technology has been around for the best part of a decade now so there are plenty of choices to help you out when you’re preparing your final mix.

So how can I measure LUFS?

There are plenty of plugins out there (including free ones) that will allow you to measure LUFS and keep track of the loudness of your mix to make sure it isn’t peaking before mastering.

We here at MasteringBOX suggest that before uploading your track to us, you aim to prepare your mix at around -18LUFS. This should leave sufficient headroom and ensure for a truly dynamic mixdown, offering the best results after mastering. What are you waiting for?

TL;DR

No metering solution is perfect and the likelihood of everyone agreeing on a common ground is about as likely 8 track becoming the next fad medium. However, LUFS does a fantastic job and I for one won’t be using anything else anytime soon. Now you just need to prepare your tracks for mastering. If you’ve got any questions or need any advice, please comment down below and I’ll do my best.

Feature image under creative commons attribution license by El Gran Dee.