Mastering Articles

What Does a Mastering Engineer Do?

Creating music involves a series of steps that come before and after recording the song in the vocal booth. One very important step in the process of music making is mastering the audio. Before any song is released and distributed to the general public, the sound has to go through a mastering engineer.

It seems to be pretty easy describing what a music producer or even a sound engineer does but often at times, the concept and necessity of having to send audio to a mastering engineer eludes most people because… what does a mastering engineer do?

Early years

In the earlier years of music production, a mastering engineer’s role was to transfer master mixes to wax so they could be used for mass vinyl production and distribution. With rapid advancements in music technology, the functions of a mastering engineer go beyond just making wax masters.

Today, a mastering engineer is required to learn mastering techniques and skills that enable them polish and enhance tracks that form a song or an album to sounds great played from any source – whether it’s an iPod or a large speaker system.

Mastering audio to give it that refined and polished sound requires that the mastering engineers use a combination of analogue and digital tools to compress or limit sound, apply or adjust EQ, enhance stereo imagery and much more.

Without mastering audio, the volume across devices would vary, such that an audio mix might sound louder from one device to the next. A mastering engineer controls the overall volume thus ensuring that the music is played at a consistent volume via any playback device.

Fresh ears

The music making process lends itself nicely to the idiom of ‘two heads are better than one’ when listening to a song. Keep in mind that when producing a song, the sound or mix engineer must listen to the same audio over and over again in order to perfect it.

This eventually makes it sound monotonous which by extension means the producer may not be able to make some necessary adjustments accurately. By passing the song to a mastering engineer, a fresh set of ears would be listening to the song and as such make necessary adjustments.

Mastering engineers are also very good critiques because they are aware of what the audience calls “good music” and their ultimate goal is to help both the producer and music artist deliver the best sounding audio as possible.


During the process, the mastering engineer treats or enhances necessary parts of the sound. Imperfections in production, mixing and recording are easily noticeable to the mastering engineer and as such need to be resolved before distribution.

In a nutshell, here is a bullet point of the functions of a mastering engineer.

  • Applies EQ, stereo imaging & limiting including final compression to the audio.
  • Balances the audio.
  • Chases the fade in’s and fade out’s in such a way that the digital silence is perfect
  • Processes every song in an album separately such that the volume of every song contained in the album is level.
  • Makes the required adjustments to the format that make the audio playable on all media
  • Removes glitches or  clicks that may have happened during the audio recording
  • Adjusts “spreads”: Spread is a term used to describe the time gap between songs.
  • Burns final master to send to the relevant client ready for mass production and distribution


Nowadays, the art of mastering has been brought to the online marketplace with various websites and studios offering mastering services based on algorithm processes.

These algorithm mastering processes are based on the type of genre you enter for your song and whilst they may present an attractive alternative in terms of turnaround time and price, it is unlikely they will be able to replicate the delicate and intricate touch of a trained and experienced mastering engineer.

Leave a Reply

Your email address will not be published. Required fields are marked *