You might not know it, but you could be playing Metallica better in your living room than the band did on record. When their 2008 album Death Magnetic became available on Guitar Hero, players noticed a significant change in quality; the sound was crisper and there was no gritty distortion heard when music gets too loud for output. Fans took to the forums, wondering why the original version seemed to have less punch and a duller sound. The answer was that the album, like most modern releases, was a victim of the ‘Loudness War’.
This is a drive by the music industry to ramp up sound recordings by a process known as dynamic range compression (DRC), which involves stretching out the dynamic range (the difference between the louder and quieter parts of a song) to the point where all portions of the audio are at the same volume. The process is more common than you might think; advertisers will often ‘stretch’ the sound to get more attention for their ads (thus appearing louder than TV shows), while it’s the de facto practice for radio stations in order to stop people constantly adjusting their volume dial. Bars and restaurants use compressed ambient music so that quiet parts are still audible in the background.
In the studio, compression can be used as an intentional effect. Imagine a singer wants to whisper their lyrics over some loud, crunchy guitars. Normally the vocals would be lost in the track, but by treating them to compression they can be heard clearly and at the same level as the guitars. Compression will also allow notes to fade away for a longer time – useful if you want prolonged chords or cymbal crashes.
The problem begins when dynamic range compression distorts audio. Their waveform (the squiggly bar seen in Audacity, etc) will look like a brick. There are no high or low parts to the song. It’s loud in its entirety. While some music such as folk and classical are more noticeably affected by it, other types may be less so (for example, punk music intends to be loud and is thus less inclined to be put under DRC). A constant release of remastered albums means that the loudness war is beginning to affect earlier works as well. The remixed edition of Iggy and The Stooges’ Raw Power counts as one of the loudest albums ever. While Led Zeppelin’s ‘Stairway To Heaven’ has a dynamic range of 35dB – from quietest to loudest part – the entire range of Raw Power is only 4dB.
The reason behind the loudness war is fear. As free music becomes easier to obtain, music labels are using any means necessary to stand out and attract larger audiences into buying more music. If an album can sound louder, the reasoning is it will make a larger impression and sell more. Engineers and producers who are concerned about sound quality will argue against this – thus, a ‘war’.
Alan Parsons, who alongside his own band engineered albums Abbey Road and Dark Side of the Moon, said in his Art and Science of Sound Recording: “light and shade is good… we respond emotionally to variation. Pop music has always been about energy. Given the option to make the music at least seem more powerful… it’s unrealistic to not expect there to be pressure from record companies, managers, agents, distributors, and many distributors to make the mix as commercially viable as it possibly can be.”
Nowadays opponents in the industry are beginning to fight back. In 2011 mastering engineer Ian Shepherd (who has mixed for artists such as New Order, Keane and Deep Purple) established an annual Dynamic Range Day to raise awareness about dynamic range compression to both the public and others in the industry. There are now a variety of videos on YouTube from other audio engineers explaining the practice, as well as internet databases that rate new releases over their loudness.
In the case of Metallica, others took control of the album while the band went on tour. The record labels, in an attempt to make their own output unique, have instead joined a chorus of over-engineered releases that are now the industry standard. Though there are several artists that resist over-compressing their albums, more of these battles are being won by the anxious executives at record companies worldwide.