Mastering is an essential part of the recording process, yet is often misunderstood by many in the music industry. In most recordings, mastering will be the final stage before music is sent for production on to formats such as CD, or distributed online to stores such as iTunes. Mastering is essentially a form of quality control applied at the end of the recording process. After a collection of songs has been recorded and mixed in a normal recording studio, it will then be sent to a mastering studio to be brought together before being delivered for manufacturing or distribution. It is common for the mastering engineer to apply processing such as a equalisation and compression, before bringing the tracks together and sequencing them in the correct order. The experience of the engineer allows them to determine the balance between the individual and artistic aspects of each track, along with how each song plays in the context of the album and any trends occurring within the current music culture. The mastering engineer will also determine the appropriate spacing between the tracks, add any relevant digital data such as ISRC and UPC codes, and then produce a final high quality master copy of the entire album that can be used for manufacturing. There are a number of factors that need to be considered during mastering session that will allow the recordings to sound their best, and for the album to sound consistent from one song to another. One of the main aspects is to adjust the tone of each track using equalisation. This will serve a number of roles. The first main purpose will be to correct any possible problems in the final mixes that may not have been noticed during the mixing sessions. Often these problems may be caused due to the room and monitoring system that was used during the mixing. Essentially every room has it’s own sound and this will affect the way in which you hear the music in that room. Certain rooms can mask or even enhance certain frequencies. This can mean that the mixing engineer may compensate for the sound of the room by adding frequencies that they are not hearing, or cutting out problem frequencies that are enhanced by the room. This can often lead to mixes that may sound great in that particular room, not translating well to other sound systems. In this situation, mastering provides an essential quality control on the recording by taking it into a different acoustically treated environment with a full range monitor system. This allows any problems that may not have been noticed during the mixing session to be accurately corrected. This role has become more vital over the last decade with more and more recordings being made in small home studios. Equalisation also allows the overall tone of each song to be enhanced to make the songs sound more consistent between each other, to sound the best they can and to be competitive with similar recording being released. It is common for many recordings to be made over a long period of time and to be recorded and mixed in different sessions and studios. So while the finished tracks may sound great on their own, they may not flow when placed in the final order next to each other. Equalisation allows the mastering engineer to adjust the general tone of each track to make them flow and sound consistent. Essentially this is a way of looking at the entire collection of songs and to view the album as a whole. So while the recording process usually focuses on one track at a time, the mastering engineer will look at how the whole collection of songs sound together, and how they will translate to the rest of the world Another common role of the mastering engineer will be to control the dynamics of each track using compression. Compression is a way of controlling the peaks in the audio and can often bring a track together, adding a certain “glue” to the sound. Compression can make many of the elements of a mix sit together more consistently, and can be used to shape the attack of many of the percussive elements of a song. The benefit of controlling the peaks in the audio is that it allows us turn up the average level of the track, making the song louder. Another more aggressive form of compression is peak limiting. As the name suggests, peak limiting is a very fast form of compression with an extremely high ratio. This means that the mastering engineer can set an upper threshold on the limiter and no audio will be allowed to pass this level. Any audio that exceeds this limit will be quickly compressed. This is the main area where the mastering engineer can add volume to a track. If we turn down the loud peaks, we can increase the average volume of the track without causing digital distortion. This is where mastering can make the volume of the tracks sound more consistent. It should be noted that compression is actually a form of distortion and needs to be applied with care. While initially a louder sounding recording may sound subjectively better when compared to a softer recording, there is always a compromise as compression/limiting can take away the dynamics of the song. This is often noticed in the effect that limiting can have on the percussive elements of a song. It is important for the mastering engineer to find the compromise between audio quality, dynamics and loudness. This is where the experience and expertise of the mastering engineer shines through. The final stages of the mastering process involves preparing and quality checking the master ready for different distribution formats. Common formats can include Digital (CD & Online Streaming), Vinyl, Apple Digital Masters (formerly Masters for iTunes) and HD Streaming. Different formats have specific requirements and it is the mastering engineers role ensure that your mix takes the best path throughout the process, achieving the highest resolution for its different delivery formats while adhering to the technical specifications and limitations of each. Knowing the required delivery formats prior to the session can allow the mastering process to cover all of the requirements efficiently while achieving the highest quality at each stage. The mastering engineer will develop an individual workflow for each individual project. The final master will also be subject to quality control that involves real time critical listening of the final audio and data integrity checks.
Mastering
Mastering Equalization
Mastering Compression
Final Masters
