When Eleven Just Isn’t Loud Enough

For over a decade now, the loudness level of commercial recordings has been increasing – to the point where even the mainstream media are noting that prolonged exposure to such music actually induces nausea. This ‘hotness’ war has caused mastering engineers to sacrifice every last bit of dynamic range in order to achieve the highest possible perceived loudness.

What Is Loudness Anyway?

To understand why this is a bad thing, you must understand the basic principles at work. An audio signal is a waveform, which has peaks, troughs and an average ‘volume’ or amplitude level. The loudest possible signal in the digital environment is 0dB. In order to get the average (RMS loudness) level as close to this as possible, the difference between the highest point in the waveform (peak) and the lowest (trough) has to be reduced – this is an extreme form of compression. However, the dynamic range naturally present in music is lost when the signal is compressed like this, which makes the recording very difficult to listen to for any length of time. Listenability is therefore sacrificed for the ‘immediate impact’ effect.

It is a basic psychoacoustic tenet that, all else being equal, we perceive a louder recording as sounding better. As people don’t tend to change the volume control on their stereo from one song to the next, a CD recorded with a lower RMS level might seem a bit wimpy compared to the previous one. However, if the volume control were raised to bring the new CD up to the apparent loudness of the first, then the quality benefits of its greater dynamic range would become obvious.

With extremely hot recordings, the levels remain very close to 0dB pretty much all the time. Bob Katz cited an example of a Ricky Martin album, which was compared to a ‘lightbulb’ – once the track started, all the level meters came on at maximum and stayed there throughout the entire song. Quite apart from the music itself, such a recording is very tiresome to listen to. For some more explanation of mastering levels and examples of some well-mastered recordings with good dynamic range, try the honor roll at digido.