[Nov. 27, 2016, updated throughout with information geared for the web.]
NOTE: The Loudness Radar is also available in Adobe Audition. Its interface, operation and settings are identical.
Ed Golya, the Emmy-award-winning audio mixer for the Digital Production Buzz, and I would often get into a discussion on how “loud” the Buzz should be. Based on my background I look at the waveforms. Based on Ed’s experience, he listens. This difference provides an interesting basis to our discussions.
The basic rule – that audio levels should not exceed 0 dB during export – continues to hold true. But there are new rules on loudness in both the EU and the US that now come into play.
NOTE: In the US, loudness levels are set by the CALM Act (Commercial Advertising Loudness Mitigation Act). “In its final form, it restrains itself to ‘incorporating by reference and making mandatory… the ‘Recommended Practice: Techniques for Establishing and Maintaining Audio Loudness for Digital Television’ (A/85), and any successor thereto…” This Recommended Practice, known as ATSC A/85, was generated by industry practitioners entirely independent of the government, actually prior to the law’s creation.
“So we’ve been ordered by the government to obey our own internally developed recommended practices for the management of loudness in television broadcast and distribution. (Dave Moulton – TV Technology )
The basic goal of these rules is that the average loudness of commercials, programs and interstitials should sound about the same. Unlike peaks, which measures the instant-by-instant maximum audio level, loudness measures the average level over time, measured in LKFS. (Average levels are about 20 dB lower than peaks.)
Definition: LKFS. Loudness, K-weighted, relative to nominal full-scale. LKFS is an amplitude level, based on dBFS and measured as LUFS (Loudness Unit, Full-Scale). 1 LUFS is, essentially, the same as 1 dB.
While it is easy to get lost in the technical details, for this article I want to show you how to measure loudness and, more importantly, how to use those measurements to improve the quality of your sound while staying within legal limits.
NOTE: If you are mixing programs exclusively for the web, this meter is even more helpful, but the settings are different. I’ll discuss web settings throughout.
THE LOUDNESS RADAR
In both Adobe Premiere Pro CC and Adobe Audition is a special filter – called the Loudness Radar. The Loudness Radar is a tool that allows us to measure average audio levels over time and, if applied to the master track, to see the audio levels for our entire project at a glance.
While the Loudness Radar can be applied to any clip or track, I recommend you apply it to the Master track; because, after all, you want to measure the loudness of your entire mix. To do this, select Window > Audio Track Mixer.
To reveal the FX section of the mixer, click the small, white, right-pointing triangle in the top left corner of the mixer.
This displays both FX and Send sections above every track. In the top portion of the Master track (all the way to the right) click one of the small triangle to reveal effects filters that can be applied to a track. Select Special > Loudness Radar.
NOTE: To remove a filter, click the small arrow, again, and choose None.
This adds the filter to the Master track.
NOTE: There are five effects slots, or positions, in each track. Make sure that the Loudness Radar is below any other filters, to allow you to properly measure the results of their effects. In this example, I’ve applied it to the second slot. If you are only applying this one effect, you can use any of the five slots.
To view the Radar, double-click the text “Loudness Radar” in the effects slot.
This displays the Radar itself. Yup. Its big. Feel free to move this wherever you have room – including a second monitor.
NOTE: To display the Loudness Radar in Audition, select a track – I generally use the Master Track because I want to monitor my entire mix. Then, in the Effects Rack, choose Special > Loudness Radar.
Click the Settings tab at the top to see the settings for the Radar. If you are measuring this for broadcast, the default settings are fine.
For the web, change Target Loudness to -16 LKFS. The rest of the settings are fine as is.
Using the Radar is easy – just play your project:
The Act says broadcast and cable projects should be -24 LKFS. When I’m mixing for the web, I want my levels around -16 LKFS. (Yeah, the web is louder, mainly because computer speakers are so lousy.)
But there is more we use this for. Notice how levels vary in the four rings? The beginning is too loud, then it gets too soft. Our goal is to have our audio float at the edge of the second ring, just before it turns yellow.
The Radar allows us to see how even, or consistent, our audio is throughout the program. This is the only tool that allows us to see all the audio in our mix in a glance, allowing us to determine where it might be too loud, or too soft.
NOTE: Yes, many times we want differences in loudness during our program. (This is called “dynamic range.”) But, even more importantly, we want the mix under our control so that we know exactly where the loud and soft passages are and that they are within the right boundaries.
This allows us to go back to our mix and know exactly where we need to tweak to get our audio levels and our mix to sound as good as it can.
The latest version of Adobe Premiere allows us to normalize our audio to match the Calm Act settings. This means that we can use the Radar to spot problems and either fix them manually, or allow Premiere to fix them for us during export.
NOTE: Loudness Normalization is worth an entire article in itself. Be sure to read the Help files before using this feature so that you understand what the settings are doing.
Unlike the audio meters, which provide only transitory data on our audio mix, the Loudness Radar helps us spot problem sections instantly, as well as offering advice on where we need to bring excessive levels under control.
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