loudness_FEATURED

The Audio Producer’s Guide To Loudness

Intro from Jeff Towne: We all know the experience - listening to the radio or watching TV, a loud commercial jumps out, sending you grabbing for the volume control. Or conversely, your favorite program is too quiet leading you to crank up the volume, even though you know louder levels will startle you as the next program starts. Variations in program levels have been a problem for public radio stations, and now the public radio world is attempting to even out this difference by implementing a new loudness standard. Adhering to this standard will soon be required when submitting programs to the Public Radio Satellite System’s ContentDepot, PRX, and other organizations, and it's also just a good tool for making sure your mixes keep a steady level.

Rob Byers tells us about the concept of Loudness, and how to use it to create better mixes that are both internally consistent and compatible with other programs in the public radio system.

 

Today as you mix audio productions you most likely monitor levels with a peak meter — those two little bars that jump up and down in tandem with the waveform — and you know those meters don’t always line up with what you hear! You look at two very different pieces of tape on the meter (say, your studio-recorded voice against an interviewee on the phone), tweak those two voices until they appear the same on the meter, and your ears tell you they play back at quite different volumes. You might decide to forego the peak meter for the RMS meter, which can provide a small advantage over a peak meter, but they too do not take perception into account. This is a problem that a new audio measurement method, loudness, can help you solve. Finally there’s a way to simplify levels.

In this article I will walk you through a number of ways you can incorporate loudness technology in your work. I’ll start with the tool that offers the most immediate improvement to your production: the loudness meter.

If you’re already sold on using loudness and want to skip to the how-to part, click here.

What’s wrong with the meter I use now?

Short answer: The meter you use now has nothing to do with the way you perceive sound.

The most common way to represent audio is to display electrical level. That usually means a waveform, a VU meter, or a peak meter — those bouncing bar graph meters ubiquitous in digital audio. The problem? These tools don’t correspond to how the audio actually sounds to our ears. It’s possible for the audio to look one way on these meters but sound quite different. Phone tape is a frustrating example of this phenomenon: on a peak meter it often looks hotter than it sounds. Modern recorded music often displays the opposite effect; it will sound louder than it looks on a peak meter, especially when matched up against voice.

Loudness meters measure audio similarly to the way humans perceive sound. The meters analyze audio taking into account duration as well as frequency — the human ear is sensitive to some frequencies (the wail of a baby, the rustle of leaves), not so sensitive to others (the rumble of a bus, the low notes of a bass guitar). That measurement is much more consistent with the way we hear. Sounds that we hear as “loud” display higher on the meter and vice versa.

The unit of measurement, the Loudness Unit [LU], actually represents an audible difference. A change of one LU is a difference you can noticeably hear — you certainly can’t say that for one dB, the unit used on most other meters.

Loudness meters also remove an issue that other meters are prone to perpetuate: interpretation.

Let’s try a hypothetical experiment. You and I are both going to deliver a piece to a radio program that requires audio to be mixed to -15 dBFS (average levels hovering around -15 dBFS on a typical peak meter). If we both try to mix to that target, we will end up with different sounding mixes, because we will interpret the target differently. Should the peak meter consistently hit -15dBFS, go through it, or just tickle it? Loudness meters remove this interpretation issue because they give a numerical readout; either you hit the target or you don’t, no interpretation needed.

Loudness meters offer another benefit: they give you a better picture of your audio when you mix in less-than-ideal environments. Perhaps you need to mix a quick spot on headphones from home or deliver some vox pop from the noisy local coffee shop. No matter how fancy the headphones you use to monitor your audio in those environments, you will be at a disadvantage when it comes to balancing elements and judging levels. Loudness meters can make up for some of what you can’t hear because you can now trust that what you see on the meter matches the true loudness of the elements in the mix.

These meters are way more useful for production purposes than the traditional peak and VU meters of yesterday. You could say loudness meters actually show you what you should be hearing!

Is anyone else using Loudness?

Loudness was first implemented in European television broadcasting half a decade ago and is the technology behind the CALM Act in the US (legislation passed a few years ago to ensure that TV commercials aren’t blastingly loud). It’s caught on in other media since — iTunes Radio and Spotify both use their own iterations of loudness technology to balance levels from one song to the next. Pandora doesn’t. Have you noticed?

In early November 2014, the Public Radio Satellite System, public radio’s largest distributor of content, adopted a loudness standard intended to bring consistency to the system and reduce level jumps between programs. The new loudness standard is set to begin some time in 2015. PRX will follow suit, as well as major producers like American Public Media, NPR, and PRI. All of these organizations are jumping on board because loudness technology will bring marked consistency to their programming.

It’s clear the audio world accepts loudness as a superior metering technology, and its great that it’s on its way to public radio. But you can start using loudness meters now to help improve your mixes. There are numerous options for integrating loudness metering into your work, from meters built directly into audio editors, to free third-party plug-ins, to super-polished paid plug-ins.

How do I get a Loudness Meter?

Adobe Audition CC and Hindenburg Journalist PRO, already popular in the public radio world, include loudness meters. Both of these meters are extremely useful, but they are each formatted differently. We’ll talk about that later, for now simply keep an eye out for the “Short Term” reading, circled in each image below.

Audition TC meter
Audition TC meter
Hindenburg Meter
Hindenburg Meter

There are also free meters available as downloadable plug-ins. I call them “free” though they are really trials or shareware. (The folks who made these put some hard work into them, show them you appreciate their efforts and pay the upgrade fee or donate.)


If you use an audio editor that takes VST and/or AU plugs (like Audition, Hindenburg, Dalet, DAVID, Reaper, Audacity, GarageBand, or Logic) look at the ToneBoosters EBU Loudness meter or the Klangfreund LUFS Meter. For ProTools, check out the HOFA 4U meter.

Keep in mind that you tend to get what you pay for. These plug-ins offer few customizable options and all minimize the size of the numerical displays, a feature I find important.

Toneboosters EBU Meter
Toneboosters EBU Meter
Klangfreud Meter
Klangfreud Meter
HOFA 4U Meter
HOFA 4U Meter

If you are willing to spend a little cash you can pick up the TC Electronic LM2n for about $149, which happens to be the meter Adobe chose to include in Audition. The LM2n is compatible with VST, AU, and ProTools plug-in formats (PT10 and up); it’s a great choice if you find yourself working in different audio platforms. TC Electronic is well established in the audio world, so support for this product should continue for some time. They offer a 14-day trial that is worth checking out before you commit to purchasing.

Many other loudness meter plug-ins are available at higher price points. They may have prettier graphics and more bells and whistles, but these features won’t offer much added value to the typical public radio workflow. They will, however, likely remain supported for many years to come. I suggest two in this category: the Waves WLM (ProTools, VST) and the Nugen LMB (compatible with newer versions of ProTools, AU, and VST). Izotope’s Insight also comes highly recommended and is compatible with just about every platform available.

Waves WLM Meter
Waves WLM Meter
Nugen VISlm Meter
Nugen VISlm Meter

Hardware meters are also available if you prefer a physical box with analog and/or digital inputs. These are mostly appropriate for studio installs, but if you are in the market to fill this need you’ll find plenty of options out there.

Check out the PRSS Loudness Tools list for a comprehensive list of meters and other tools.

An aside for you ProTools users: it wouldn’t surprise me to see a loudness meter included in a future update. Loudness is becoming ubiquitous, and the major platforms are all getting in on the act. Nuendo, Audition, and Hindenburg all have, so it makes sense that ProTools will follow suit… eventually.

What do I do with it?

First and foremost, I’ll set you up so you can actively mix your project — changing levels and making balance adjustments as the audio plays back live. Install the plugin (instructions can usually be found on the plugin’s website), open your project, and insert the plugin on the master track. If your session doesn’t already have a master track, make one. All of the tracks in your project will route through this master track, so it’s crucial for monitoring levels as you mix. Check out the videos below for specifics:

Loudness meters display measurements in a unit called Loudness Units Full Scale, or LUFS (As in “I lufs loudness!” You’ll occasionally see this stated as LKFS, but that’s the same as LUFS). Loudness Units is used when describing relationships. For example, the difference between -24 LUFS and -20 LUFS is 4 LU. If you see a number with “LUFS” or “LU” following, it means the measurement incorporates perception (the frequency and duration characteristics of the human ear).

It’s important to recognize that there’s a difference between the unit used on peak meters (dBFS) and LUFS. The unit dBFS (Decibels relative to Full Scale) is solely a measurement of electrical level, without any of the benefits that loudness brings. Our new world is a LUFS world!

To get started, focus your attention on the Short Term measurement. There’s a bunch of information displayed on most loudness meters, but for improved consistency in the typical radio piece you can simply use the Short Term measurement for mixing. It is an average of a rolling 3-second time window, usually displayed as a number, and it works really nicely with the pace of speech. If you ignore most everything else on the meter and concentrate on this measurement, along with the clipping notification on the peak meter (clipping is bad), you will be just fine.

What number should you aim for? Well, the PRSS already made this decision for us: -24 LUFS. That number happens to correspond pretty nicely to the old PRSS standard of average levels at -15 dBFS, so if you’ve previously mixed this way, you shouldn’t notice too much of a change in peak levels. You will, however, notice your mixes sounding more consistent, and your old meters may read above or below -15 dBFS.

Remember This

If you remember one thing after reading this article, it should be this: mix voices to -24 LUFS on the Short Term meter. I specify voice because that is the common denominator in the majority of public radio-esque programming. It will help with consistency from one program to another if you target voices to the same place. Remember this, use good production practices, and rely on your ears. Keep the voices at -24 LUFS and the rest of the audio in your piece like music, ambi, and sound effects will fall in line around them.

A bonus: the target of -24 LUFS gives quite a bit of space between the typical speaking level and the maximum level where audio will clip (also called “head room”), so peaks aren’t too much of an issue. That said, you still need to manage your peaks, you can’t just ignore them, because clipping (red lights on peak meters) can cause audible distortion. Volume automation or use of a limiter are often great ways to solve this problem. The easiest way is to follow the PRSS standard and aim to keep peaks at or below -3 dBFS.

To make things a little easier, most meters allow you to set the target level with presets. These presets will sometimes adjust the point at which the meter will change colors which gives you a visual reference when mixing – perhaps green when the target is being hit, and red when it is too high. On most meters the presets are listed relative to the international standard they are based on. The PRSS standard of -24 LUFS happens to be compatible with the ATSC A/85 standard (the standard set by the CALM Act), so pick that preset when available. You don’t have to choose a preset, but it is an easy way to quickly customize the meter and make it easier to use.

Remember: mix voices to -24 LUFS on the Short Term meter!

 

 

Integrated Measurement – The Big Average

If you produce programming for national distribution, listen up. The Integrated measurement, described here, is the primary metric that PRSS and PRX will use to determine compliance with their new loudness standards.

Now that you know to mix voices to -24 LUFS on the Short Term meter your pieces will show improved consistency. You will be able to get phoners, narration, field tape, music — all of your elements balanced easier and quicker than you could with a peak meter alone. You might stop now, but there’s a little more to it.

The Short Term measurement focuses on a three-second window — it constantly updates the average loudness over the past three seconds. Short Term is super helpful as you mix a piece in the moment, but it can also be informative to know the average or Integrated loudness of the entire piece from start to finish. Integrated loudness is a decent predictor of consistency between pieces of audio. It’s certainly not foolproof, but if two pieces of audio have similar Integrated measurements and are produced with good production practices, odds are they will sound consistent with each other.

Geek note: Integrated measurement doesn’t allow silences or super low level (like quiet ambi) to influence its measurement. It actually excludes audio below a certain loudness so the measurement isn’t artificially skewed.

There are three methods for obtaining Integrated loudness. The easiest (yet most time-consuming) way is to play the piece in real time, start-to-finish, while measuring with a loudness meter on the master track. Most loudness meters have the ability to actively measure the Integrated loudness while audio plays through it in real time. Some plug-ins require you to start and stop the Integrated measurement, while others simply synchronize the meter with the audio editor: when audio plays in the editor the meter begins measuring.

Another way to get the Integrated loudness is with an offline, faster-than-real-time measurement. Not all audio editors and plugins allow for this, but Pro Tools does, so I’ll use it as an example. I’ll also assume that you have installed a third-party loudness plug-in. To do an offline measurement you need to mix the audio down to a single file, either through a bounce or some other method (there are many ways to do this depending on your audio editor). Import that mixed audio into a ProTools session. Under the AudioSuite menu find the loudness meter plugin and choose it. Highlight the audio file in your session, and click “Analyze” in the meter. The meter will quickly process the file and you will be presented with the Integrated loudness of the piece.

The last way is similar to the second method and requires you to have the audio mixed down to a file. You will use an external application to measure the file. You simply drag the audio file on to the program window, it analyzes the file and reports the measurements. On the Mac I like to use r128x (it’s a confusing webpage – click the “Download” link on the right-hand side to get the program).

Loudness Normalization

There is yet another way to achieve the magic Integrated target loudness of -24 LUFS… but it is not without drawbacks. You’ve probably heard of peak normalization, the process that moves the highest peak in a piece of audio to a chosen level and adjusts the rest of the audio relatively. This process is based on electrical level, considering only the peaks of the waveform, not how the audio sounds. Peak levels have little to do with how we perceive the audio. Enter loudness normalization.

Loudness normalization is a similar concept, but uses perception instead of electrical peaks to normalize the audio. It measures the Integrated loudness then moves the level of the piece of audio up or down until the desired Integrated loudness is achieved. That means the entire file is gained up or down in one fell swoop.

Spotify and iTunes Radio both use loudness normalization for their streamed content — it’s why those services sound so consistent. iTunes also has a function called SoundCheck which uses loudness normalization on the music stored on your computer. If you use the free version of Spotify, you’ve probably noticed that the ads play SUPER loud. That’s because the ads aren’t loudness normalized! iTunes Radio does normalize their ads and it’s a nice experience (as far as listening to ads goes).

For radio production, you would typically use loudness normalization after mixing to make sure the final product hits the target loudness exactly. You would want to mix towards the target anyway, but the loudness normalization step afterward would put you spot on. You could also use it to normalize individual elements in your piece prior to mixing.

To be clear — loudness normalizing a final mix will not change relative levels between elements in the mix. If the mix includes a poor level shift between two interviewees or two sections in the mix, loudness normalization will not improve that, it only adjusts the level of the overall mix. The poor level shift will still be present after loudness normalization as all elements are shifted up or down equally.

Another drawback to loudness normalization involves peak management. Because this form of normalization focuses solely on the Integrated loudness of the audio, it doesn’t necessarily take into account what happens to the peaks. With lower-end tools it’s certainly possible for a file to be loudness normalized so that peaks end up clipping. To prevent this, most normalization tools include a limiter to prevent clipping. Preventing clipping is good — but sometimes the limiter can have a negative impact on the sound of the mix.

Loudness normalization is integrated into a couple of DAWs, but it’s not widely available in that form. Adobe Audition includes a rather powerful tool for this purpose, which uses a limiter to prevent clipping. It’s the most powerful tool I’ve seen integrated into a DAW in terms of customization, but that also means there are quite a few options to maneuver around.

Hindenburg takes a unique and user-friendly approach. It calls loudness normalization “Auto Level” and allows the user to apply normalization either manually or automatically to clips and recordings.

First you have to specify the target loudness, which Hindenburg only allows you to do by choosing among presets. Make sure you have upgraded to the most recent version of Hindenburg PRO. Older versions of Hindenburg PRO aren’t compatible with the PRSS standard of -24 LUFS. To set the target loudness, go to Preferences and choose the Advanced menu, then select “US” in the dropdown box. This sets the target loudness to -24 LUFS for voice and -25 LUFS (just noticeably lower) for music.

To use Auto Level manually, select a clip and then choose “Auto Level” in the Tools menu and watch the waveform level change. To enable it automatically, turn on “Perform automatic leveling after import and record” in the Preferences/Advanced menu. Now, after you import a file or make a recording, you’ll see the waveform adjust to match the target loudness. It’s pretty slick!

If you just have Hindenburg Journalist, never fear. That version automatically presets to -23 LUFS, which is the European standard. Though you will hear a difference between -23 LUFS and -24 LUFS they are so close that your mixes will still be compliant with the new PRSS spec.

There are just a few standalone loudness normalization tools available and many are pricey. The TC Electronic LCn is a recent standout, but it’s not cheap. Auphonic is a cloud-based service that offers loudness normalization and a bunch of very interesting audio processing features for a monthly subscription. Most other standalone normalization tools worth their salt are much more expensive.

If you decide to implement loudness normalization, don’t get lazy… you must continue to use your ears. Relying on loudness normalization can work, but you give up all of the benefits that loudness meters bring, such as balancing different elements within a mix. The best approach is to:

  • actively mix with a loudness meter
  • keep loudness normalization on hand to prep audio before a mix
  • implement it only if you come into the process late and can’t make adjustments to the mix itself.

What about recording in the field?

No portable recorders currently implement loudness meters, so there is not yet a loudness solution for recording in the field. But that’s okay — you’ll want to make loudness adjustments when it comes time to mix anyway. Record at a comfortable level, and after you import the files you can actively mix with a loudness meter. If you have access to loudness normalization, you could quickly process your audio to -24 LUFS before mixing.

I LUFS Loudness! (say it out loud)

There you have it. You now have access to new loudness tools to bring consistency to your work. When presented with different audio elements in a mix — a voice recorded in the studio against a phoner, for example — you’ll be able to balance them so they sound consistent. You’ve also got a tool to help when mixing in less-than-ideal environments. If you produce national programming, you now know how to meet the new distribution guidelines using a combination of metering and loudness normalization.

As with any new tool, it may take some time for you to adjust. The meter will be the biggest change, since it looks and reacts differently than what you are probably used to. You’ll quickly find that loudness meters do indeed match up with what your ears tell you, or, if you are in a place where you aren’t able to listen carefully, what your ears can’t tell you!

If you have questions about implementing loudness in your work, please post a comment below and don’t hesitate to contact me via email or Twitter. I strongly believe loudness technology will improve the public radio system and I enjoy helping folks figure out these new methods.

Resources you might find useful:

PRSS loudness site

Florian Camerer BBC video

Getting on the Level with Levels Webinar from PRX and AIR

Why You’re Doing Audio Levels Wrong, and Why It Really Does Matter – from Adam Ragusea at Current.org

Comments

Leave a Comment

  • Daniel J. Lewis

    2.10.15

    Reply

    Nice post, but I think -24 is too quiet. That’s the standard for broadcast media, but Internet media is going for the louder standard of -16 LUFS. This is actually where iTunes and several other players will target when you enable their automatic loudness tools.

    • Rob Byers

      2.10.15

      Reply

      Hi Daniel, thanks for writing. I think we are both on the same page in many ways.

      You are correct, -24 LUFS is the standard for broadcast use and is the new standard for the PRSS, the the largest distributor of public radio content to member stations for broadcast.

      I agree that -24 LUFS is too quiet for podcast/mobile use and that -16 LUFS is a good choice for podcast/mobile. However, I highly recommend producing (editing and mixing) at -24 LUFS because that gives much more headroom (space between the highest peaks and clipping) than -16 LUFS. Only once is the mix is complete and sounding great do I recommend that the -16 LUFS version be created. For many in the public radio world, this will be a natural workflow, as they will produce for both radio and mobile. For those just producing for mobile, I still think it’s a good idea, because, again, of headroom.

      (I’ll continue in the next comment)

    • Rob Byers

      2.10.15

      Reply

      For those that are curious on how to get to -16 LUFS, there is quite a bit of information out there on the subject. The podcast community is full of folks who write and podcast about their craft. I’ll list two sources here:
      http://www.producenewmedia.com/podcast-loudness-processing-workflow/
      http://podcastaboutpodcasting.com/podcast-loudness/

      As for how -16 LUFS was picked, I believe it’s for two reasons. The first is because iTunes and Spotify use it, as you say. The second is because -16 LUFS happens to work really well with the electronic capabilities (headroom) of the majority of mobile devices. Thomas Lund figured all of this out so we don’t have to… and published a paper on it here: http://www.tcelectronic.com/thomas-lund-discloses-new-research-on-audio-loudness-for-mobile-tv-and-podcast/

      Others may pick slightly different numbers, but for now Lund has made a very clear case for -16 LUFS. And as you point out, it is quickly becoming the accepted target in podcasting.

      • Jay Allison

        2.11.15

        Rob, per your responses to Daniel’s question, if you mix at -24 LUFS (or any other standard), what quick methods would you recommend to create other master files at a specified higher (or lower) level, e.g. -16 LUFS?

      • Rob Byers

        2.12.15

        Hi Jay,

        I recommend the following steps, first outlined by Thomas Lund in the article mentioned above, to get to -16 LUFS when producing for mobile:

        – Produce/edit/mix at -24 LUFS
        (It’s easier to produce at this lower level because you have more headroom. It also gives you a product compatible the PRSS spec for radio broadcast.)

        – Manually bring up audio that is very low (think: If I were in the subway, with the volume of the voices comfortably set, would I lose any important low audio in the piece? This is not an issue for the vast majority of spoken word pieces).

        – Limit that file/mix at -10 dBFS.

        – Add +8dB of gain.

        – Voila! You now have a file that is -16 LUFS and is ready to be converted to mp3/aac/you name it.

        For those who would like a little more detail, the links above should help.

        Rob

      • Martyna Laska

        1.04.16

        Hi Rob. I’ve got a question regarding discussed remix of an audio mixed at -24 LUFS into one at -16 LUFS. You suggest to limit peaks at -10 dBFS and then boost the level to make it -16 LUFS. That sound allright to me, as long as we don’t have many peaks that goes above -10 dBFS. If we do though, wouldn’t we change the overall sound quite significantly by limiting it? My concern is – isnt it better to do the opposite order, so mix for -16 LUFS first and then just level everything down to -24 LUFS? Of course I know that the dynamic range is compromised in this case, but still isnt it the better solution, knowing that our -24 LUFS mix peaks much higher than -10 dBFS? Thanks !

      • Rob Byers

        1.05.16

        Hi Martyna,

        Thanks for your question! I think you’ll find that audio targeted consistently at -24 LUFS (especially spoken word) will not have many peaks above -10 dBFS that are significantly audible when limited. Yes, you will see the results of limiting when looking at the waveform, but the reduction in those quick transients are noticeable to most listeners. In other words, the target of -24 LUFS is low enough that limiting at -10 dBFS won’t adversely affect the sound for most productions.

        If a production is not well mixed, doesn’t do a good job of consistently targeting -24 LUFS, and has periods above -10dBFS that are longer than short transients, then yes, the limiting would be audible.

        As for mixing for -16 LUFS first then gaining down to -24 LUFS… I believe that workflow loses many of the benefits of producing at the lower level. Producing at -24 LUFS allows you to make important decisions about dynamics and balance that you may not be able to make if you are trying to manage headroom with limiters. And, some folks may not have the technical ability to produce at the higher level because they will not be familiar with the operation of a limiter – they’d prefer to rely on a loudness normalization tool (like Izotope RX) to do the limiting for them.

        To wrap up – I recommend producing at -24 LUFS because it avoids headroom problems, requires no special knowledge of limiters, allows you to easily mix a consistent and dynamic mix, and results in a broadcast-ready mix. The podcast/online delivery file can then easily be created with the steps described above or a loudness normalization tool.

      • Rob Byers

        1.06.16

        Quick correction – meant to say the following in that first graph:

        “…the reduction in those quick transients IS NOT noticeable to most listeners.”

  • Marco Raaphorst

    2.10.15

    Reply

    Very nice read.

    I feel that the -24 LUFS is tricky since HDTV uses the -23 LUFS norm. A lot of metering systems are calibrated to -23 LUFS as well. I believe this should be enough headroom for any classical piece with huge amounts of dynamics. In a way it’s a bit of a disaster that their are now at least 2 norms: -24 and -23… 🙁

    What you’re writing about Short Term versus Integrated measurements is also interesting. I felt Integrated was better but after reading this I am no longer sure. Integrated might be great way for leveling a track or a whole album (music), but anyone who is broadcasting something for hours and hours should run into problems soon. Short Term will be better I guess. For iTunes or Spotify I believe Integrated would be best, per track and stored as meta-data with the track.

    Another cool thing about Short Term is that you will be more aware of any spikes in the signal. Like static noises. Intergrated would not at all respond to a few spikes which can harm any listener in a serious way.

    I am looking forward to the future. Although we’re still using metering which will also show DB maybe we can soon stop using that. Maybe we can even start using simple color codes for giving us information about the level being ok or not. But again, that -24 or -23 LUFS norm is a little of a bummer in my opinion. I am European, but it shouldn’t be a problem 🙂

    Well, thanks a lot for the article!

  • Rob Byers

    2.12.15

    Reply

    Hi Marco,

    Thanks for writing! The current spec for loudness in commercial TV in the US is -24 LUFS, which was set by the ATSC A/85 standard. That’s one of the reasons -24 LUFS was chosen for the PRSS spec – it’s already an industry standard in the US and they wanted something that would make life easier for those stations that are both public radio and public television facilities. The EBU r128 standard used in Europe, which I think you are referencing, is -23 LUFS.

    The fact that both of these are considered industry standards is good for audio producers, reporters, and the like, because the vast majority of loudness meters incorporate both of these options as presets. As mentioned in the article, all you have to do is use the “ATSC A/85” preset in your meter and it will be compatible with the PRSS spec.

    (there’s something about the comment tool that makes me split these in to two posts… sorry about that)

  • Rob Byers

    2.12.15

    Reply

    ….
    In the end, for our audio production purposes, the difference between the US and European standards isn’t really THAT big of a deal. If someone accidentally produces at -23 LUFS, it’ll still sound fairly consistent with everything else that’s produced at -24 LUFS.

    Thanks for your other comments as well. Very nice to hear from you.

    – Rob

  • Marco Raaphorst

    2.16.15

    Reply

    Thanks Rob. This makes total sense to me. I am still trying to find the right tool for me though. I am using Propellerhead Reason a lot. But currently I use Ableton Live for this kind of metering.

  • Sarah Kate Kramer

    3.06.15

    Reply

    Hi Rob – Thank you for this! 2 questions. In your instructions above to bump up the mix to -16, you suggest adding +8db of gain. Is that equivalent to moving the volume point on the master track in PT up +8db?

    Also, I have been using the HOFA meter to measure integrated loudness, but I’m interested in using an offline app like r128x. I tried to download it but I’ve never installed a program in terminal before and I’m a bit confused. Do you know of a tutorial or step-by-step guide?

    Thanks!

    • Rob Byers

      3.10.15

      Reply

      Hi Sarah,

      Yes, the r128x page is a bit confusing! I believe you can download the r128x GUI version and it’s an easy install from there. Look under the Binaries section for “r128x-gui”… here’s the link in case you can’t find it: https://www.dropbox.com/s/tzkwccqhkybsn3q/r128x-gui-0-21.zip

    • Rob Byers

      3.10.15

      Reply

      As for your PT question, the answer is: it depends.

      If you have PT 10 or above, I suggest you limit the file using an AudioSuite plug then use Clip Gain to add the 8dB of gain. Export that clip/file and you are ready to go!

      If you have an earlier version of PT (this will work for 10 and above too), you can add gain using the master bus – as long as the incoming audio is limited already. Just make sure there are no other plugins following the limiter that will affect the sound… you want the limiter to be the last plugin in the chain, or else you risk adding gain and distorting the resulting file.

      Regardless of where you do it, remember to limit first, then add gain – don’t reverse the process or put anything in between!

  • Jim

    2.14.16

    Reply

    Doesn’t mixing at -24 Lufs and then changing to -16 Luf also bring up floor noise?
    Don’t we run the risk of dealing with our mix only to find unwanted noise in the final mix at -16 Luf?
    Thanks

    • Rob

      2.16.16

      Reply

      Hi Jim,

      Thanks for your question! Technically, yes, that is true – the noise floor will increase. Loudness normalizing a piece of audio from -24 LUFS to -16 LUFS would raise the noise floor approx 8dB.

      That said, I don’t think it is an issue that is a case for concern.

      Today’s digital gear – even moderate quality gear – is pretty quiet. The noise floor is low and will not present an issue to spoken word and other typical “public radio-style” productions. Only the most dynamic and quiet productions will encounter that noise floor – I’m thinking of pianissimo passages in a string quartet, here – and those would likely take a different approach to production for reasons other than the noise floor.

      If it helps, I’ve been working with this workflow for a couple of years now, producing both to -16 LUFS and -18 lUFS, and have not had any noise floor issues.

      Good luck!

      Rob

  • Bobby

    3.05.16

    Reply

    Nice and indepth article. Thank you very much. One just simple question from me. What is the preset i have to use for the TC electronics loudness meter plugin in Adobe Audition for Radio productions ( Ads, promos …) Thanks Heaps.
    Cheers.

    • Rob Byers

      3.07.16

      Reply

      Hi Bobby,

      Assuming you are producing to a -24 LUFS spec a la public radio distribution, the “ATSC A/85” preset will set up the meter appropriately. It might be called something slightly different.

      Rob

  • Scot Singpiel (@TheyCallMeScot)

    5.10.16

    Reply

    Rob, Thank you very much for such a detailed post. I’m just begining to mess around with using loudness to improve the sound of my mixes and this was so helpful. Thanks again.

  • Rob Byers

    5.24.16

    Reply

    If you have questions about loudness for podcast mixing… check out this article here on Transom: http://transom.org/2016/podcasting-basics-part-5-loudness-podcasts-vs-radio/

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