Loudness Metering Standards

Hi post posters!

Check out this introduction to loudness metering to learn about meeting industry standards using WLM+.

What standard do you use?


WLM+ is my savior, I’ll be lost without it.
Using it almost daily with Surround Audio delivery for DCP when asked for Leq-m 84 standard levels.


There are quite a few different types of metering systems offered on the WLM+ meter. I have read the loudness metering Standards document, which gave some clarification on the EBU vs ASTC, I’ve long known the differences of VU vs PPM, I also own The Dorrough Loudness Meter, but the document failed to get into the specific of the rest of the options. While I have basics on ASTC for TV, EBU** is more for music, what are all the variations for: eg. +9 vs +18?, OP?, ARIB?, Discovery?. The only one that makes sense is the ‘Sony Playstation’. What are the different types best suited for? When would you want to use the 9 vs 18 mode? All the manuals tells you is that they exist and the range of the controls, no explanation as to why to use one or the other. I live in Canada, if that make any difference?

@MusicMachineX3, welcome to our forum!
These are broadcast loudness standards.
Different broadcasting organizations and associations provide guidelines and standards which productions need to comply with in order to be approved for broadcast.
These presets match the standards of the different organizations and associations in the market, and help post production engineers and mixers comply when handing in projects.
Does this answer your question?

Hi Yishai

It helps,. But Where do you find the ’ Different broadcasting organizations and associations … guidelines and standards which productions need to comply with in order to be approved for broadcast.’? to know which one to use.

My main use is - Music for Radio airplay or downloading such as Spotify, Apple etc. At this time not much for Movies or games.



This is not a tool for listening to or watching streaming services or playing downloaded media - it is for the production side.

You have no use for it with Music for Radio airplay or downloading such as Spotify, Apple etc.

When a production submits a TV episode, movie or even music to Netflix for instance - the audio mix must comply with Netflix’s Loudness standards.
The production can check if the mix complies using WLM+, and also add some limiting where needed.
If it does not comply, WLM+ gives a warning and the mixing engineer can fix any issues until it does.

Netflix / EBU / Discovery / Sony and more have slightly different loudness standards and guidelines, which they provide to the productions that they contract.
These standards are represented as presets within WLM+.

Apple Music have their own mastering tools, with built in loudness specs.
Spotify list their loudness specifications here.

Hi Willi,

with loudness measurement the question is not so much “what material am I mixing (music, movie, documentary)” but “what platform/network am I mixing for”. And then it’s up to you, to contact the network and ask what standard they use. So if you’re mixing music, it doesn’t matter if it’s country or hip hop. What matters is where the music is going to be released. If it’s going to be released on Spotify, use the spotify preset (latest WLM update added presets for spotify/youtube/apple). If it’s for a local radio station, then only they can tell you what specs they require.

ITU = International Telecommunications Union
ATSC = Advanced Television Systems Committee (USA)
ARIB = Association of Radio Industries and Businesses (Japan)
EBU = European Broadcast Union
OP = Operational Practice by FreeTV (Australia)

The not often mentioned CKOD Standard…

Cops Knocking On the Door telling me to turn it down usually manages my lounges levels quite quite a lot. :upside_down_face: :rofl:

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