When Nirvana’s Nevermind came out, it was touted as one of the loudest albums ever released. Today, if that album came onto your iTunes playlist after Death Magnetic, you’d have to turn your speakers up considerably to hear it.*

Psychological studies have shown that a recording’s loudness dramatically affects how much people like a song and how likely it is that a person will stop on a certain radio station. The solution? Limiting: a process which effectively turns up the quietest parts of a recording, automatically raising its overall loudness. A limiter is one of the last pieces in the mastering signal chain and arguably the most important.

Done properly, limiting can add energy to a song. Taking it too far a la Death Magnetic, however, may cause ear fatigue, a subconscious phenomenon akin to reading under dim light, straining the listener’s ears and making him or her want to turn off the music after extended listening periods.

Metallica‘s latest has received a flood of criticism and media attention regarding the presence of over-limiting and digital clipping, an unpleasant-sounding distortion that occurs when a sound medium is overloaded beyond its volume limit.

The audio community has been debating the so-called “loudness war” for years but never before have consumers been able to hear the difference for themselves. Enter Guitar Hero: World Tour, which allows users to access an unmastered version of Death Magnetic – and it sounds a lot better.

Mastering engineer Ted Jensen defends himself:

“In this case the mixes were already [over-limited] before they arrived at my place […] I would never be pushed to overdrive things as far as they are here. Believe me I’m not proud to be associated with this one, and we can only hope that some good will come from this in some form of backlash against volume [being seen as the most important thing].”

It is hard to say who is responsible. The engineers who worked on the album have otherwise stellar track records. In any case, Death Magnetic may represent a new kind of revolution: one that gets quieter.

Personally, I find that clipping can benefit some recordings, but this new Metallica record took it too far. Add to this the fake-sounding drums and we’re left with one of the worst sound major recordings in recent years. What do you think? And to those of you who aren’t audio engineers: did you notice?

Also note: Another result of the loudness war is that many record labels have released “digitally remastered” versions of classic albums in order to compete with today’s recordings. If you want to compare Nevermind to Death Magnetic, use the original release for full effect.

*Soundcheck notwithstanding.

Sources: Tape Op (Nov/Dec ’08), AllMusic.com