Ask pretty much any musician planning to make a record what mastering is all about and they'll probably include 'making it sound loud' as one of the more important mastering tasks. The problem is that as every generation has tried to 'out-loud' the previous one, we've reached the point where all this compression, limiting and distortion has had a seriously detrimental effect on the way recorded music sounds; a phenomenon that has become known as 'the loudness wars'. Compression and limiting has legitimate applications, of course, but excessive use in the cause of loudness squashes the peaks to allow higher average levels, and this robs the music of dynamics and impact if the actual playback volume is taken out of the equation. Put very simply, music mastered with less emphasis on 'loudness at all costs' invariably sounds better than its heavily compressed/limited counterpart when played at a similar subjective level; and the emphasis here is on 'subjective' because, until now, metering systems didn't really help gauge that very important parameter.
As Hugh Robjohns details in his article on the subject in this issue, US mastering engineer Bob Katz, during the 2013 New York AES show, declared that the loudness wars are over. This has been made possible by a shift in metering methodology. It all started with broadcast, with TV commercials becoming unbearably loud as their producers went on to exploit the headroom normally reserved for explosions in feature films. Something had to be done, and now we have the technology to do it automatically.
To cut a long story short, new methods of loudness evaluation have been developed that can automatically meter and, if necessary, adjust audio material to maintain a consistent subjective loudness, as opposed to matching simple peak or RMS levels. This type of system is being taken up by the radio and TV broadcast industry as well as certain Internet music streaming providers. Apple have their own Sound Check system built into iPods, which aims to do much the same thing (though you still have to turn it on), and they've reinforced that with the inclusion of automatic loudness adjustment by default in their new iTunes Radio music streaming service. There are still some wrinkles to be ironed out before this actually becomes standardised, as Hugh's article goes on to explain, but what it means in practice is that if you go all-out for loudness when mastering, the chances are that your mix will actually sound more feeble when 'loudness normalised' by one of these new systems.
Of course, excessive compression and limiting used in the name of art, rather than the blind pursuit of loudness, is still fine — dance tracks can pump all they like if that's the way the producer wants them to sound. We can all breathe a sigh of relief that we can now mix and master tracks with a view to getting the best sound, without having to accept the 'loudness compromise', and be fairly confident that, in the not-too-distant future, their level will match that of other material when played back on radio, TV or a portable music player. I urge you to read Hugh's article, as loudness normalisation is a genuinely big deal and marks a significant change in the way music will be mastered and 'consumed' in the future.
Paul White Editor In Chief