Understanding Loudness Part 6 - Using Loudness Meters For Music And Post Production
We are seeing loudness normalisation in more workflows, not just broadcast audio but music streaming services, too. There is a wide range of Loudness meters out there now, and we thought it would be helpful to provide a round-up of the different options that are now available. We know it is not completely exhaustive, but it covers the main players in the loudness meter plug-in sector.
What Has Gone Before
In Part 1, Why Do We Need Loudness? We clarified what we mean by loudness, investigated how our hearing works, why we have changed our audio metering systems and presented the solution to loudness changes that consumers complain about.
In part 2, The Development Of One Loudness Standard, we covered the development of one loudness standard. We explored how we arrived at a loudness measurement algorithm that works just like our ears and the various criteria we use to define and guide us when working to the new loudness delivery specifications, including K Weighting, the differences between Momentary, Short-term, and Integrated loudness, and the importance of True Peak and Loudness Range.
In part 3, Calibrating Your Monitors, we covered a key part of delivering loudness-compliant content: calibrating your monitors. We looked at how our monitoring should be configured and explained bass management and what your sub should be doing before moving on to a practical demonstration of calibrating your monitoring with a sound pressure meter.
In part 4, Creating Loudness-Compliant Mixes For Broadcast And Netflix, we covered some tips and tricks for mixing to the broadcast loudness standards for a wide variety of genres. We included examples and demonstrations and explained the importance of what Mike describes as ‘loudness planning’ before ending with some specific tips and tricks for mixing short-form content like adverts, trailers, and promos. Finally, we moved on to cover the Netflix delivery spec brought to the world of Loudness.
In part 5, Preparing Content For Music Streaming Services, we covered loudness online content and music streaming services, including the various standards for online content, loudness normalisation, album normalisation, and how to prepare music tracks for music streaming services with three free video tutorials.
Our Selection Of Loudness Meters And How To Use Them
In this final part, we are going to list our selection of loudness meters in alphabetical order, and as we mentioned at the start, please note that this isn’t an exhaustive list. Where we have them, we will include tutorials and reviews of each of the meters.
Avid Pro Limiter
An oldie but a goodie, Avid’s Pro Limiter furnishes Pro Tools users (i.e., it’s AAX only) with a fast, friendly, highly efficient true peak limiter built for music and post-production. Manual and Auto Release settings facilitate tailoring to the dynamic timing of the source material, while the Character knob introduces analogue-style saturation, and the histogram visualises the loudness profile over time. Up to 7.1 surround is supported, and the included Loudness Analyzer AudioSuite plugin analyses complete tracks and reports on their peak loudness levels at a click. Note that it only supports the EBU R128 spec, so if you want to cover other loudness delivery specs like ATSC A/85, this isn’t the tool for you. Here is a summary of the Avid Pro Limiter features…
Clean and transparent sound — Sits well in the mix while maintaining tight control over output levels.
Character knob — Add soft saturation to get more loudness and a higher amount of gain reduction without the unwanted digital artifacts of standard brick wall limiters.
EBU R128 loudness metering — Normalize broadcast audio to EBU specifications using a variety of metering, including True Peak, Integrated Loudness, and Loudness Range.
Full surround support — Process up to 7.1 surround mixes in up to 192 kHz resolution, with full metering on all channels.
Front/rear linking mode — Allows you to work more easily with surround sound material and link channels for more consistent level management.
AAX DSP optimised — Pro Limiter handles monster-sized Pro Tools|HDX mixes with ease, delivering exceptional sound quality and DSP efficiency.
Back in 2013, Russ took a look and, of course, a listen to the Avid Pro Limiter and found a couple of hidden surprises. Then Mike followed up and concentrated on the loudness metering features.
HOFA 4U Meter Fader & MS Pan
The HOFA plug-in is part of their free 4U Suite, so nothing is going to beat this one on price. Although you can only have one loudness meter in an instance of the plug-in, there is nothing stopping having three instances; one with the Integrated, a second with Short Term and a third displaying Momentary. Like the Avid Pro Limiter, it only displays the EBU R128 scale, so it is great for the UK, Europe and any other territory that adopts the R128 standard. But it is still a useful guide for other territories as the various standards are very close to each other. This free plug-in suite also has much going for it....
Precise metering (peak, hold, EBU, LRA)
MS decoder - use this and then use conventional plug-ins to process using MS.
Trim, fader and mute function
Stereo-mono switch - use this on a Master fader to check your mono compatibility. A feature rarely found in a free plug-in
Analyse peak & EBU R128 levels via drag and drop of audio files
Innovative panorama function: this is the panner that you can also use for “more than stereo” panning
Changeable plug-in window size - Getting a little more common but rare on free plug-ins.
PC and Mac, 32 and 64 Bit DAWs.
iZotope Insight
iZotope’s Insight is a comprehensive metering suite for post production and broadcast applications. Insight provides an extensive set of audio analysis and metering tools, including a loudness section with full history, logging and automation features. Insight, of course, is much more than just a loudness meter with 2D and 3D Spectrograms, True Peak Meters, Stereo Vectorscope, Surround Scope, and Spectrum Analyser as well.
In this free tutorial, I show the essentials of using the iZotope Insight plug-in on Pro Tools for loudness compliant metering and explain how to ensure your mix meets the latest standards, such as BS 1770-3, ATSC A/85, EBU R-128 and more.
A lot has happened since iZotope launched Insight back in November 2012 including the implementation of loudness delivery specs including EBU R128 and ATSC A/85. With the release of Insight 2 the plugin has been completely overhauled and highlights include…
New Intelligibility Meter — iZotope designed this to help users understand how an audience will experience the dialogue. We understand that powerful DSP measures the intelligibility of dialogue compared to the rest of the mix to ensure that the dialogue level can be clearly heard in different listening environments.
A new look - They have completely overhauled the GUI so that Insight 2 matches the other iZotope products. You can resize and customise the new user interface, which has been redesigned to be easier to read at a glance
Multichannel support - Insight 2 now supports multi-channel formats up to Dolby Atmos 7.1.2.
Global loudness standard support - Insight 2 supports loudness targets for latest standards including EBU R128, BS.1770-1, BS.1770-2/3/4, ATSC A/85, and OP-59.
In 2019, iZotope released Insight v2.1, which included a Netflix preset. Following Netflix's update to its audio mix specifications, Netflix recommended that content delivered for its streaming service meet a dialog-gated loudness target of -27 LKFS. You can read more about the Netflix delivery spec in our detailed article including the response we received from Netflix, too.
Insight 2 comes with many presets, which iZotope calls Layouts. Version 2.1 comes with a new Target named "Netflix" that enables the Dialogue gate and sets the LRA targets to the expected values. Here’s a screenshot of the Netflix Target…
Nugen Audio MasterCheck Pro
MasterCheck Pro is designed to be the complete solution for optimising your mixes for today’s music delivery services. Streaming apps, download stores, websites and podcasts all use data compression, loudness matching or both. These processes can affect your mixes in various undesirable ways: your loud punchy mix could end up quiet and flat, or suffer clipping or distortion. The good news is you don’t just have to mix for CD and hope for the best. MasterCheck Pro reveals problems ahead of time and enables you to deliver masters perfectly tuned for specific playout systems.
These days, engineers are often required to deliver multiple or different masters for a specific track. You may have a general-purpose master that will be sent out for creating CDs, another one specifically for use in a broadcast mix, and yet another meant for a streaming service such as Spotify or Apple Music.
Each platform can require a different deliverable spec regarding its true peak level and program loudness range. In addition, these masters may even possibly be ‘adjusted’ downstream to fit a specific requirement. So, needless to say, it's within our best interests to make sure we hit the target, thus avoiding any unwanted surprises.
In 2018, Nugen Audio released MasterCheck Pro v1.5 with enhancements embracing support for the Apple AAC (Advanced Audio Coding) iTunes Plus native OS X codec and also the PSR (Peak to Short-Term Loudness Ratio) measurement update to AES Engineering Brief 373.
Nugen Audio VisLM
In this 5-minute free video tutorial, Paul Maunder gives an overview of NUGEN’s VisLM loudness meter plugin. This tutorial is aimed at new users or anyone considering transitioning from another loudness meter to VisLM.
Being able to accurately measure loudness is a critical part of the post-production mixing process, whether you’re working on something for TV, radio, streaming platforms or even a podcast.
NUGEN Audio VisLM includes presets for a wide variety of international loudness standards, including EBU R128, ATSC A/85, OP59, and Netflix. In addition, VisLM can be fully configured and tailored to suit any custom specs.
With up to 24 hours of loudness history linked to the timecode in your DAW and comprehensive True Peak metering, VisLM is well suited to complex post-production mixes where compliance with a defined loudness requirement is critical.
VisLM also includes up to 7.1.2 surround support and, as you will see in the video, provides a comprehensive and highly configurable set of loudness metering tools.
The Rewritable Memory Edit Mode is absolutely amazing. It enables users to make small corrections to a mix without having to re-analyze the whole programme. I also love how I can resize the window and all the additional options they have added to the plug-in.
Nugen Audio Vis LM v2.8.3 changed the Stereo Netflix preset to reflect the changes in Netflix Best Practices 1.1 and Delivery Standards v3.3. Netflix now specified a maximum LRA of 18 instead of 20.
V2.8.3 also brought a major new feature - Flags. This allows users to navigate through True Peak and short-term/momentary loudness alerts and add manual flags for other points of interest. Now Nugen Audio has had Alerts for quite a while, but you would be forgiven for missing them as they are very easily missed because they showed up as little red dots in the Loudness History display.
Flags do not replace Alerts. They enhance them and add three new things…
They convert the little red dots that represent Alerts into vertical lines with Flags enabled.
You can now navigate between each flag, and a small dialog box appears in the bottom right-hand corner of the loudness history window, showing in red what the issues are at this point of the mix.
You can create your own flags. As you are playing through, click on the Flag button, and you will notice that an orange line appears at that point on the timeline in the Loudness History window. It’s good that they have chosen a different colour for manually placed flags from the flags which come from Alerts. The Flag navigation controls include orange ‘manual’ flags as well as red alert flags and notice that you get little arrows top and bottom of the Loudness History Window.
Finally v2.8.3 brought, what was at the time, an undocumented feature, which can save you both time and money. If you have ever used the feature in VisLM where you can ‘overdub’ a section of a mix and VisLM will recalculate the integrated Loudness and LRA on the fly to reflect the changes you are making to the mix when dropping in and fixing some patches, then you will know how much time it saves not having to reanalyse the full mix.
But for this feature to work, you effectively have to play the whole mix into the real-time VisLM plug-in so that it captures the data on the mix and is ready to update it when you undertake the changes.
What if you haven’t done that? Maybe the mix came from another facility that doesn’t use VisLM. It will take you the duration of the mix to load the data onto VisLM, which on long-form content could be an hour or more, to be ready to use the ‘on-the-fly’ loudness data update feature.
What if there was a way to harness the offline, non-real-time features of AudioSuite plug-ins to complete this analysis in double quick time? Well, this feature does just this.
You can analyse the full mix file using the AudioSuite version of VisLM. Then you will see the new yellow button light up, telling you that the plugin has data ready to export. When you click on that button in the AudioSuite plug-in, a corresponding Import button appears in the real-time plugin. When you click on the Import button, the real-time plugin asks you to play the audio from the timeline to identify where the clip is on the timeline, and once the blue progress bar has filled up, you can stop playing the audio. The real-time plugin will load the loudness analytics from the AudioSuite plugin, and you are ready to go.
You can see how all these features work in this video...
For people working in film production and especially trailers, Nugen Audio has included the Leq(m) measurement for both the TASA and SAWA delivery specs as you can see from the image below.
You can learn more about Leq(m) in our article Leq(m) Loudness - What Is It And When Is It Used?
RTW Loudness And Mastering Tools
RTW Loudness Tools offers metering and loudness display plug-ins for mono, stereo, multichannel, and surround applications up to 7.1 at sampling rates up to 96 kHz. It also offers all the widely used Loudness, PPM, and TruePeak measurements and scales.
Anyone who is familiar with RTW’s hardware meters like the TM3, TM7 or TM9 will be at home with these plug-ins. With their 50 years of experience, you will see that the hardware and software products use the same model, and RTW have worked hard to make configuration and operation as similar as possible.
In this first free video tutorial, I cover all the features that are common to both RTW Loudness Tools and RTW Mastering Tools, including how to set them up, either from scratch or by using one of the factory presets. In addition, I cover how to resize the plugin window as well as configure and use of the buttons like Start and Stop/Reset. Finally, I cover how to set up the standalone versions of RTW Mastering Tools and RTW Loudness Tools.
In this second free video tutorial, I cover in detail how to set up and use each of the instruments in RTW Loudness Tools and RTW Mastering Tools: the PPM Instrument, the Loudness Sum Instrument, the Loudness Numeric Instrument, the Loudness Range Instrument, and the Stereo Correlator Instrument.
In this third free video tutorial, I cover in detail how to set up and use each of the instruments that only come in RTW Mastering Tools. These are the Vectorscope Instrument, Surround Sound Analyzer Instrument, Real-Time Analyzer Instrument, and the multi-channel version of the Correlator instrument, as Loudness Tools only has a stereo Correlator Instrument.
TC Electronic LM1n, LM2n & LM6n
The LM1n is the baby of the range, and the LM2n and LM6n are almost identical. In fact, only two things set them apart: channel format compatibility and logging. The LM2n measures any mono or stereo signal while the LM6n supports mono, stereo and 5.1 surround, but they both use a clever radar display for the loudness history.
Understanding TC Electronic LM1n Metering Plug-in
TC Electronic’s LM1n measures loudness using the exact same algorithm as LM2n and LM6n. It displays the key numbers for Program Loudness (I) and either Loudness Range (LRA), Max Momentary Loudness (M), Max Short Term Loudness (S) or Sliding Loudness (10 Sec) as well as True-Peak clipping. TC Electronic developed the LM1n as a simpler solution for those who have found that they sometimes need to deliver content that complies with a certain broadcast standard, including outside broadcast production workflows.
The advantage of the LM1n is that it doesn’t take up much screen real estate, as you can see from the comparison between the LM1n, LM2n normal size, and the LM2n Big display. The LM1n’s simpler display also makes it ideal for multi-skilled staff and for use in other sectors, like mastering for music streaming and albums.
In this free video tutorial video, which was previously a premium tutorial, I cover how to use the baby in the TC Electronic plug-in loudness metering family - the LM1n showing how to use the LM1n in CD and album mastering workflows. As part of the process of assembling an album, the mastering engineer will adjust the relative loudness of each track so that when the album is played as a whole, the listener doesn’t have to adjust their volume control because some tracks are too loud whilst others are too quiet. Now with a loudness meter like the LM1n on the CD Master preset, you can run each track through the LM1n and get a quantitive measurement of the loudness of each track. To make this even easier and quicker it is possible to use the LM1n is a non-real-time mode. For example, in Pro Tools, you can use the AudioSuite version of the LM1n to analyse the clip in non-real-time.
Understanding TC Electronic LM2n and LM6n Metering Plug-ins
The new LM2n and LM6n meters retain the radar view from their predecessors and offer a number of new features, such as dedicated settings for Max Momentary (M) or Max Short Term (S) Loudness display and a ‘Big’ version of the Radar, which is very useful when working at a distance from the screen.
The LM6n also features detailed logging for documenting delivery specs in accordance with major broadcast standards, which is key when producing content for broadcast.
In this free video tutorial video, which was previously a premium tutorial, I cover how to use the TC Electronic LM2n and LM6n plug-in loudness meters although I will be using the LM6n as the two plug-ins are so similar, but I do make it clear when a feature is only available on the LM6n. Although there are a number of loudness meters that include a histogram feature that displays loudness history, the radar display interface is unique to TC Electronic loudness meters so I spend some time exploring how to read and interpret it as it folds back on itself so that you get a continuous display of the loudness history, which is also relevant to anyone using hardware meters with the TC Electronic radar display option fitted like the TouchMonitor.
Waves WLM Plus
The Waves WLM Plus is a popular loudness meter that covers many bases, although it doesn’t have any histogram display. The upside of this is that the plug-in’s GUI takes up less screen real estate.
In this video review from 2014, I examine the Waves WLM Plus Loudness meter, which adds a True Peak Limiter and a Trim option to the Waves WLM loudness meter.
The Waves WLM Plus Loudness Meter plug-in provides loudness measurement, metering, correction and adjustment tools for broadcast, movie trailers, games, packaged media and more. Fully compliant with all current ITU, EBU and ATSC specifications, the WLM Plus offers Momentary, Short Term, Long Term and True Peak readouts, as well as a warning and logging system that keeps track of your levels, alerting you when you’ve exceeded them - or fallen short.
WLM Plus also features Gain and Trim controls for correcting loudness levels and a True Peak Limiter, which can avoid the need for additional equipment or software.
In this free video tutorial from 2015, I show how to use Waves WLM Plus in Pro Tools to get your broadcast mixes loudness compliant to the appropriate BS1770 loudness delivery spec like EBU R128 or ATSC A/85.
The Waves WLM Plus supports Leq(m) measurement and comes with a TASA Movie Trailer preset but not a SAWA Advert preset, so I made a custom preset by simply adjusting the Target level down from 85.0 to 82.0 and saved it as a new preset.
You can learn more about Leq(m) in our article Leq(m) Loudness - What Is It And When Is It Used?
Youlean BS1770 Loudness Meter - Free And Pro Versions
The Youlean Loudness Meter a free loudness meter plug-in and unlike some other free loudness meter plug-ins runs on macOS and Windows and supports AAX, VST and AU plug-in formats.
What Youlean Say About Their Loudness Meter Plug-in
Works in almost any DAW - Available in VST2, VST3, AU and AAX plugin formats, Windows and macOS operating systems.
Helps you comply with strict loudness requirements for the Film and TV industry.
Helps you get the correct loudness levels for upload to Spotify, YouTube, Apple Music and Tidal.
Find out what regulation your country is using and use ITU-R BS.1770-4, EBU R128, ATSC A/85, OP-59, ARIB TR-B32 or AGCOM 219/09/CSP preset to comply with the standard.
Use the AES loudness preset to ensure that you sound great on Spotify, YouTube, Apple Music, Tidal, or when streaming.
GUI too small or too large? No problem; freely resize or scale the plug-in
You can always switch to mini mode if you find graphs too distracting. Fit precisely for your workflow.
Inspect the audio dynamic. Using the peak-to-short-term loudness algorithm, you can detect a squashed or incorrectly compressed mix.
There are now two versions…
Free Version
TV presets
LU, INT, TP, LRA, PLR measurements
Resizing, scaling GUI
Mini view
True peak and loudness graph
Automatic loudness overdub
Mono, Stereo, and 5.1 channel support
Pro Version
TV presets
LU, INT, TP, LRA, PLR measurements
Resizing, scaling GUI
Mini view
True peak and loudness graph
Automatic loudness overdub
Mono, Stereo, and 5.1 channel support
Streaming presets
Dynamic graph
PDF export
Readout focus
Custom alerts
Faster project saving
Advanced settings
Lifetime FREE updates
30 days money back
Price $47
System Requirements
Windows
Windows 7 and above
Supports AAX, VST2 and VST3 plug-in formats
MacOS
10.7 and above
Supports AAX, AU, VST2 and VST3 plug-in formats
How To Get The Free Youlean Loudness Meter
Go to the Loudness Meter page of the Youlean website and click the Free Download button. This will take you to the Free Download page, where you can choose between a Windows or Mac installer.
You don’t need to provide an email address. Once downloaded, you can run the installer. On the first launch, you will be asked if you want to receive news and updates, which you can decline if you so wish.
Zplane PPMulator
This low-cost solution from Zplane has the advantage of taking up very little screen real estate but doesn't include a histogram feature. It can be set to EBU R128 or either of the 2009 or 2013 versions of ATSC A/85 standards, between them covers the loudness delivery specs for most of the world.
PPMulator is a cross-platform plug-in meter, which exactly mimics the look and feel of a professional broadcast Peak Programme Meter (PPM) in a variety of broadcast formats. This plug-in provides a calibrated workspace for recording, editing, mixing and mastering and is much cheaper than a hardware meter,
PPMulator also offers EBU R128 and ATSC/A85 loudness metering and batch audio file processing. It offers one of the cheapest Loudness meter solutions too.
Customisable and resizable layouts and channel labeling
Audio file batch processing
Automated peak logging with export
Mono gain trim to M3 (-3dB) or M6 (-6dB) standards
Phase correlation meter & Goniometer
Reference tone generator for meter alignment and calibration
Multi-channel support up to six channels
In 2015, I took a tour around the zplane PPMulator XL plug-in Pro Tools and found it a versatile, cost-effective metering plug-in with options for both loudness and my beloved BBC PPM, as well as a number of other options.
Conclusion
We hope that this six part series will prove helpful for people wanting an overview into loudness, in both the audio post production workflows as well as music mastering for CDs and music streaming services.