METALLICA's latest album, "Death Magnetic", was officially certified double platinum by the Recording Industry Association of America (RIAA) on June 28, 2010 for shipments in the United States in excess of two million copies.METALLICA drummer Lars Ulrich told The Pulse of Radio in an October 2008 interview that he didn't understand the controversy that had broken out over the audio quality of "Death Magnetic" shortly after the LP's release. Some fans and publications had accused the group and producer Rick Rubin of mixing the album at such a loud volume that the music is distorted and difficult to listen to. But Ulrich said that he's more than happy with the way it turned out. "I listen to this record, and I listen to it every couple of days," he said. "And when I hear it, it puts a smile on my face and it blows me away, and I don't understand what people are talking about. Somebody told me the other day that there were 12,000 people that had signed a petition to remix the record. We've sold two and a half million copies [worldwide] of 'Death Magnetic'. You do the math yourself." A number of fans said online that they prefer the versions of the CD's tracks prepared for the Guitar Hero video game, which are mixed differently. Ted Jensen, the engineer who mastered the album at Sterling Sound in New York, responded to fan complaints that the CD is too loud and the audio is pushed to distortion levels by writing, "I'm certainly sympathetic to your reaction, I get to slam my head against that brick wall every day. In this case the mixes were already brick-walled before they arrived at my place. Suffice to say 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 above all else." Mastering is the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device, the "master," from which all copies will be produced. Blame for the sound quality has been laid at the feet of the band itself, producer Rick Rubin and his recording engineer, Greg Fidelman. METALLICA will end the "Death Magnetic" world tour later this fall with shows in Australia and New Zealand before taking a break.