A look through the data on the Dynamic Range Database (opens in new tab) will give you a few figures to show the extent of the situation. Dynamic range, then and nowīefore the R 128 standard, decades of squeezing music’s dynamic range ended up leaving us very squashed. Streaming platforms have got onboard with this somewhat, with Spotify and YouTube normalising to -14 LUFS, Apple Music to -16 LUFS, and Amazon normalising to between -9 and -13 LUFS. The EBU’s recommendation is for streamed music to aim for a target level of -23 LUFS. To get the actual measurement, the signal is K-weighted with a high-pass filter and a 4dB increase above 1kHz.

The Full Scale value (LUFS) measures an absolute loudness and is referenced to 0dBFS. The new system replacing RMS level (for our purposes here), is a system of Loudness Units (LU). If a piece of music has an average loudness above that level, it is to be turned down if below that level, it should be turned up. This specified a way to measure the perceived loudness of an audio signal, and crucially, a target level for that signal. In 2010, the European Broadcasting Union issued EBU R 128, a recommendation for a system of Loudness Normalisation. With the Peak level set and unchangeable, the incentives were aligned for engineers to raise the RMS value as loud as they possibly could.

There was a definite peak level that a piece of digital music theoretically couldn’t cross: when those 16 bits were full of 1s. In the days of the CD, music was carried with an amplitude range across 16 bits. During the loudness wars, the highest peak was a set value.

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