03-08-2015, 05:10 PM
A quick explanation of EBU R128:
In order to discourage advertisers from using compression to make their commercials way louder than the music on the radio and TV, EBU R128 is an international broadcast standard that requires broadcasters to normalize playback by average loudness rather than by their peak level. So until a few years ago everything on the radio was normalized so the highest peak landed just under unity gain, so heavily compressed audio was subjectively much louder.
The current standard has become law in several nations requires broadcasters to normalize the average loudness of audio to -27 LUFS. LUFS isn't precisely the same thing as RMS because it's calculated slightly differently but you can think of it the same way. Broadcast material that is on average louder than -27 LUFS will be turned down, and vis versa. Heavily compressed audio is now played back at the same subjective level, which severely punishes the perceived quality and makes it sound dull and unexciting. This is why you're starting to see music turn up on the top 40 charts with larger dynamic ranges than we've seen in the past.
In addition to loudness normalization, as I mentioned in my comments, the standard also requires the true peak level of outgoing audio to be no greater than -1 LU. Think of LU as dB and LUFS as average dB over time. The true peak is a more sophisticated method of detecting peak levels that catches spikes in level between samples, but I'm not 100% sure how it works. Basically this is to prevent accidental clipping during broadcast, and it also prevents your audio from clipping when you convert it to mp3. Lots of the really early mp3s sounded so crappy due to an incomplete understanding how the algorithms were affecting the audio.
Hope that's helpful and I'm glad you're showing an interest in learning.
In order to discourage advertisers from using compression to make their commercials way louder than the music on the radio and TV, EBU R128 is an international broadcast standard that requires broadcasters to normalize playback by average loudness rather than by their peak level. So until a few years ago everything on the radio was normalized so the highest peak landed just under unity gain, so heavily compressed audio was subjectively much louder.
The current standard has become law in several nations requires broadcasters to normalize the average loudness of audio to -27 LUFS. LUFS isn't precisely the same thing as RMS because it's calculated slightly differently but you can think of it the same way. Broadcast material that is on average louder than -27 LUFS will be turned down, and vis versa. Heavily compressed audio is now played back at the same subjective level, which severely punishes the perceived quality and makes it sound dull and unexciting. This is why you're starting to see music turn up on the top 40 charts with larger dynamic ranges than we've seen in the past.
In addition to loudness normalization, as I mentioned in my comments, the standard also requires the true peak level of outgoing audio to be no greater than -1 LU. Think of LU as dB and LUFS as average dB over time. The true peak is a more sophisticated method of detecting peak levels that catches spikes in level between samples, but I'm not 100% sure how it works. Basically this is to prevent accidental clipping during broadcast, and it also prevents your audio from clipping when you convert it to mp3. Lots of the really early mp3s sounded so crappy due to an incomplete understanding how the algorithms were affecting the audio.
Hope that's helpful and I'm glad you're showing an interest in learning.