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An Overview On Loudness In Audio Post Production And Pro Tools

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There are two loudness debates raging through our industry at the moment the first has to do with the loudness wars and music mastering, “how can I make my track louder than yours” and then there is the problem in broadcast channels where different programmes are at different loudness and so the viewer at hem is constantly having to adjust the volume on the TV remote, especially when the ad breaks come up when we get the “I want my ad louder than anyone else’s” war. 

Now it is the second area I will be focussing on in this post as there are a number of moves to change the workflows, practices and standards to move away from normalising to peak level and over to normalising to loudness.

So in this post I am going to put together some links and thoughts to help the community to get to grips with this new set of standards, the changes to the workflow and the standards that we will need to work to.

So lets start with the standards

There are a number of standards but is doesn’t seem so crazy once you realise they are variations on the initial standard the ITU-R BS1770-1

  • ITU-R BS. 1770/1 is a recommendation that defines a method for the calculation of ‘loudness’, and is the basis for most regional localisations of loudness measurement including those in America (ATSC), Europe (EBU), Japan (ARIB) and many others (Brazil, Australia etc.).

  • ITU-R BS. 1770-2 represents the current version of the ITU standard, revised to include the relative gating methodology of EBU R128 (although using a G10 rather than G8 value).

  • ATSC A/85(Advanced Television Systems Committee) is the North American recommendation referred to in the CALM act, that takes full effect in the US at the end of 2012 and uses the ITU-R BS. 1770/1 basis of measurement in it’s original form.

  • EBU R128 (European Broadcasting Union) is the European recommendation, which takes the ITU R BS. 1770/1 measurement ads adds in a complex gating system to discount low level audio under certain situations. VisLM is also capable of operating in ‘EBU mode’. A standard ITU-R BS. 1770/1 meter may not necessarily have this option.

Other documents

Here is a greater ‘starter for ten’ a 2 page guide for beginners from the EBU called 10 things you need to know about loudness

This leads onto to a link to the main EBU Loudness homepage which is the home of the EBUR128 standard that is being adopted in Europe and covers metering specs the various loudness descriptors, guidelines and numerous articles.

Videos

One of the best resources for videos on this subject is from Rome Calling which was an audio and loudness seminar held in 2011 staged by TC Electronic. I have posted on this back in December and included the videos from the conference from gurus like Thomas Lund, Florian Camerer & Richard van Everdingen

Software

Here are some links to various plug-ins available for the Pro Tools platform for loudness meter plug-ins. I will be doing a comparative review soon on these different plug-ins. But for now here are the links. Download the demos and have a go yourself.

BS1770 compliant meters

Other loudness meters