Mastering is the final creative process in the production of a piece of music. The song is written, recorded, mixed and finally mastered. The mastering engineers job is to provide an objective view on the sound of a piece of music and make an experienced decision on what processing can be done, if any, to improve the quality of the sound, as well as preparing the tracks for their intended medium (a CD album for instance.)
How is the Equipment Different?
Mastering facilities should contain accurate, full range monitoring systems and well designed and acoustically treated rooms, to get an as near-perfect frequency response as possible. This then allows the engineer to make confident decisions on the mix. They should also contain high quality analogue and digital equipment so the engineer is well equipped to deal with many different types of music and audio formats.
All mediums that music is delivered on, whether it’s vinyl, CD, mp3, tape or anything else, has a maximum level of amplitude that cannot be exceeded. The listener can then use the volume control in their playback system to adjust how loud the sound comes out of their speakers. If the volume control was fixed on all playback systems, there are certain processes that can make the music appear louder.
Compression and brick wall limiting can in effect squash the sound, making the loud parts quieter and the quiet parts louder. When this is brought up to the maximum level of the medium, e.g. 0 dbfs for digital[ed. note: Decibel Full Scale, the maximum loudness in digital systems] the track appears louder than before, albeit likely to be lacking in transient detail, punch and dynamic range.
The more it is squashed, the more it begins to sound like a ‘wall of sound’ rather than ‘punchy’ and dynamic. EQ can also be used to make things appear louder, as our ears are more sensitive to certain frequencies (those that are most prominent in speech for example.)
Where is the Dynamic Range?
Over the years, masters have become ‘louder.’ Competition between record labels to produce loud masters has caused many modern chart records to become almost devoid of dynamic range, to the point where people are complaining of ear fatigue.
There is a common misconception that mastering engineers are to blame. Most will actually advise against over-compression and limiting and explain to clients the negative effects it can have on their music. Some companies, such as Platinum Mastering Online actually provide 2 masters for their clients if they wish, one retaining the natural dynamics and one that has been mastered to a modern commercial level.
Will there be an end to the loudness wars? Who knows, but as long as mastering engineers continue to educate their clients and spread the word, there is hope yet.