![]() So it is still the case that you should be careful with your audio before you let it out, and only be left with an easy level shift to make it fit some arbitrary scheme dreamed up by a bureaucrat in Brussels. Typically these are Orban Optimods, and most broadcast engineers set them up differently, according almost to their own whims as far as I can tell. One of the primary reasons for this is that all broadcast chains have a final processor on them that will 'fix' the output, regardless of what you did. Guess what? That doesn't work at all! They're still all over the place. So the correct process for doing this is initially to normalize your file to 0dB (because this is the reference point that the Hard Limiter uses), and then apply Hard Limiting so that the Maximum Amplitude is -9dB, Insert Boost is 0dB, the Lookahead time is 7ms and the release time is 200ms (fine for speech). ![]() The idea is that all TV programmes should have similar sound levels, the adverts shouldn't deafen you, and that you can change channels at will without leaping for the volume control. This is why the BBC has been remarkably reluctant to accept it, despite every other broadcaster in the world seeming to think it's wonderful. All of these issues could be avoided in the first place with sensible setting of levels, and a bit of judicious limiting - and it's these things that need to be understood, rather than blindly following the results of a system that attempts to emulate your ears - but ultimately can't. Paul's example is typical of what happens when somebody doing the audio manages to make it 'compliant' without understanding exactly what's happened in the process. (and non-compliance) may be I should explain a bit more, and I'll apologise in advance for it being a bit of a rant. If the source audio requires significant gain to meet your defined (I) target - there's no fail-safe. In any case the multitrack Match Clip Loudness option (ITU-R BS.1770-3 mode) does not include an option to define a True Peak ceiling. Without the limiter (and of course depending on available headroom) - you run the risk of overshoots and/or clipping. That's a significant amount of supplimental added gain. You are also asked to create an alternate master for online streaming. If any such added gain results in True Peak ceiling overshoots - the limiter engages and maintains compliance.Ĭonsider this - you may have a finished piece for broadcast with ATSC A/85 compliance requirements (-24 LUFS/ -2 dBTP). Gain is added (or subtracted) based on the measured (I) loudness relative to the defined (I) target. When you define an Integrated Loudness target and a True Peak ceiling - the source audio is measured in it's entirety. Basically Loudness Normalization is measurement, gain, and limiting (if necessary). The supplimental Limiter included in the Match Loudness module makes all the difference.
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