Saturday, December 20th, 2008 | by matthew mcglynn
There was a great End Rant in Tape Op about the latest Metallica album, Death Magnetic. Mastering Engineer Paul Abbott of Zen Mastering wrote,
The outcry over the un-listenably loud level of Metallica’s Death Magnetic CD has become one of the more visible occurrences of the “loudness wars” in the mainstream media… now, a lowest-common-denominator threshhold has been crossed and the problem has been pushed in our faces.
I don’t pay much attention to the mainstream media, and I don’t pay any attention at all to Metallica — in fact it’s safe to say that I get 100% of my Metallica news from Tape Op, which thankfully means I don’t get very much at all. So I’d missed the outcry. Hell, I’d even missed the release of Death Magnetic.
In a hurry? Scroll down to find the audio clips comparing Death Magnetic CD vs. “Guitar Hero” audio. Disclaimer: prepare to be ill.
The story caught my interest. As Paul noted in his rant, the loudness of the CD was made more notable by the near-simultaneous release of an alternate mix — with much more conservative limiting and compression — via Activision’s “Guitar Hero” game. Suddenly, A/B comparisons illustrating the casualties of the loudness war can be easily made. For example, see below.
An associate of mine provided loaner copies of both mixes of the album. A few minutes of research at Last.fm revealed that the most popular track is “The Day That Never Comes,” so I loaded both versions of that song into Pro Tools.
Sure, it’s a metal song. Maybe it’s just really that loud, you might be thinking. But no, the Guitar Hero mix shows plenty of dynamic range. And, not to spoil the surprise, it sounds a lot better too.
To be clear, the core problem with the Death Magnetic CD is not that it’s loud. The problem is that it sounds like crap.
Let’s do some comparative listening. There are two ways to do it: matched volume levels (in which the two versions sound equally loud), and matched gain levels (in which both versions are output at unity gain, and the CD version is a lot louder).
Caution! The second half of the “equal gain” clip is much louder than the first half! Turn down your playback volume!
Both clips contain an excerpt of the Guitar Hero mix followed by the same section of the CD mix of “The Day That Never Comes.”
Here’s a picture of the waveform for the two mixes of this excerpt. The Guitar Hero mix (on the bottom of the screenshot) shows moderate changes in dynamic level, and plenty of transients. The CD mix, on the top half of the screenshot, is brickwall-limited — the entire segment is at maximum volume.
To match volumes for the “Equal Volumes” clip, I used a VU-meter plug-in in RMS mode, and reduced the gain on the CD mix until the two versions, panned hard L and R, were closely matched. The gain difference was staggering: 10.7dB! (see screenshot) A 10dB change requires 10x as much power to produce, and equates to roughly doubling the volume.
The “Equal Volumes” clip contains the Guitar Hero excerpt (at unity gain) followed by the CD excerpt (at -10.7dB). You won’t notice a change in playback level, but you will hear distinct differences in the quality of the sound. The distortion on the CD mix is apparent. Every snare drum fill makes my headphones sound broken. The CD mix is aggressive, for sure, but it doesn’t sound good.
Zooming in to examine the waveform, it becomes obvious why the CD mix sounds the way it does. The relatively smooth waveform of the game mix is replaced by a jagged, exaggerated line. The rounded forms of the game mix are gone — there is nothing round about the CD mix, which is comprised almost entirely of vertical lines. The CD mix is comprised entirely of transients.
Curiously, the CD mix even has transients where the game mix does not — see the vertical spikes in the top waveform that have no corresponding spike below. That’s just noise: artifacts of the compression and limiting process.
Consider that the vertical changes in the waveform correspond to vibrations in the air, and therefore to the movement of a loudspeaker cone. The CD mix requires that your speakers spend the entire song oscillating between their maximum and minimum excursion points. Your eardrums, too. No wonder the CD mix is so fatiguing. Listening to the CD mix is literally a lot of work.
Paul Abbott, in his Tape Op piece, quoted a statement by Death Magnetic mastering engineer Ted Jensen in which Jensen claims no responsibility for the sound of the CD. I found the origin of this statement — a private email attributed to Jensen, posted without his permission to a Metallica forum and quoted extensively around the web.
I wouldn’t have been inclined to pin the blame for the CD mix on the mastering engineer, anyway; the few MEs that I know are uncompromising in their pursuit of fidelity. The only way they would output something sounding as bad as Death Magnetic is if the mixes they were given sounded worse. Which was actually Jensen’s point.
Listen, there’s nothing up with the audio quality. It’s 2008, and that’s how we make records. [Producer] Rick Rubin’s whole thing is to try and get it to sound lively, to get it to sound loud, to get it to sound exciting, to get it to jump out of the speakers. Of course, I’ve heard that there are a few people complaining. But I’ve been listening to it the last couple of days in my car, and it sounds fuckin’ smokin’.
There you have it.