What is Mastering?

Mastering is the last step in the audio creation process. It takes stereo mixes and prepares them for distribution.

Within this process most people view the main goal of mastering as creating a cohesive, balanced body of work; but it’s so much more than than this.

Technically, this means when you go from one song to the next, it feels the same in tonality, balance, and loudness.

Experienced mastering engineers are able to do this easily by using tools such as Equalizers (EQ’s), Compressor, Exciters, and Limiters to help each song sound balanced while also bringing out different parts of the mix that are pleasing to the ear.

Below is a picture of a specalized Mastering EQ.


( Above is a picture of a “Millennia NSEQ-2.” This EQ has been used for mastering for years because of its versatility in frequency choices as well as having the option of it being tube driven or solid state driven. )


But mastering is so much more than just creating balance and level, think of mastering as putting the “icing on the cake.”  

If there was no icing on the cake, what would it taste like!?

What mastering is not


People often describe mastering as “magic”, “polish”, “glue”, “fairy dust”, and the list goes on.

The majority of people, even within the music industry don’t fully understand what mastering “is” and what it “is not.”

So it might be easiest for us to quickly discuss what mastering “is not” in order to help clarify what “it is.”


  • Mastering is not mixing. Mastering works off the final stereo mix, also known as a “Two-Track.” Mixing works off a “Multi-Track” which involves the ability to manipulate each instrument individually.

            ( See two photos at the end of this list that show a “Mixing Session” and a “Mastering Session.” )

  • Mastering is not a guarantee that your song will sound great if your mix is bad.
  • Getting things loud is not the main goal of mastering.
  • Mastering is not an optional part of the music creation process.
  • Mastering is not a preset or a plugin or an automated system. These things don’t listen to your actual mix, so it’s impossible to actually master a song and best serve it.
  • Mastering is not something you should let your mix engineer do, if they claim they can do a “quick master.” This will often destroy the mix you have worked so hard on.

( You wouldn’t let someone who is not a mechanic take apart your engine just because they changed a tire one time. A silly example but it’s true. )


( Above is a picture of a “Mix Session.” In a mix, the engineer has control over all elements in the song. Each instrument can be adjusted – where-as mastering works off of a stereo “two-track” of the mix. )


( Above is a picture of a “Mastering Session.” During mastering, the engineer works off the final “two-track” of a mix. A mastering engineer can only adjust the balance and level of the songs as-a-whole. )

What mastering is


Mastering is difficult. It requires a skill set and experience that many do not have. At the mastering stage you must have a creative mind that engages both logic and emotion.

It requires right brain thinking as well as left brain thinking. What Mastering is not, as described above, is a list of common misconceptions that often confuse and miss the very “art of mastering.”

When it comes to mastering, it does not always mean we have to have cohesiveness or perfect balance. This is another misunderstanding of mastering as a whole.

Balance and cohesiveness is only one part of the equation when it comes to mastering.

Mastering is about creating an enjoyable experience for the listener.

Some of our most memorable moments in life are far from balanced and perfect.

If we think of life in itself – what makes it great, many times it’s the messy, dynamic, beautiful, sad, loud, soft, somber, exciting that’s so enjoyable.

The best music reflects these emotions as they connect deep within each human. If we translate this thought into mastering, the best masters help convey these feelings to the listener.

A great master needs to take you somewhere. A great master will keep you engaged. A great master will take you on a journey from start to finish.

The modern view of mastering has become hyper focused on creating an identical experience from start to finish which has created many sterile forgettable songs.

If we water mastering down to simply limiting and taming in hopes of creating technical perfection, we have missed the whole point of music and art.

How does mastering take us somewhere?

An experienced mastering engineer can make sure that an album moves from song-to-song in a dynamic way.

A quick example would be by making one track slightly softer than another track.

This can allow for the listener to experience build-up and suspense, which is often very enjoyable.  

This same thought-process can also be applied throughout a single master, where the start of song is softer and the end of a song louder, this can be done with proper use of automation.

See the photo below for an example of what song-to-song dynamics could look like visually.


( Above is an example of two songs that build in volume. The far left, darker green track, is the first track and is softer, with minimal compression and limiting. The far right, lighter green track, is louder. You can visually see the waveform grow from track one to track two. This is a simple way to build album dynamics and help make a master feel like it’s going somewhere. )

What does mastering ask us?


Mastering should challenge the listener and ask questions.

A few questions we can ask that will help us define mastering are as follows:


  • Does the master move you?
  • Does it make you feel something?
  • Does it alarm you?
  • Does it disturb you?
  • Does it convey something beyond sonics?


These questions all point us in the right direction to a great master and often these questions are neglected when talking about the very definition of mastering.

How do we master for today?


Technically, mastering can be achieved by adjusting balance and level, but music so often begs for something more.

The history of mastering started as a safety net. Back in the 1940s the first mastering engineers stumbled into a line of work that created a whole industry.

When music began to be cut to vinyl, transient peaks could totally wreck the very machine that was cutting the vinyl.

In addition, if the transient peaks were not controlled the consumer could experience pops, skips, distortion, and poor playback quality if proper attention was not given during the cutting process.

This was when the first sonic adjustments began to happen at the mastering stage.

Compressors and Limiters were introduced as tools to help prevent peaks from ruining the listeners experience.

The goal was to retain the integrity of the original recording while helping it translate to the consumer.

See a photo below of what “Transient Peaks” look like in a song and then what the peaks look like after compression and  limiting.


(Above is a photo of a mix that has transient peaks. These peaks are the loudest parts of the song and are the spikes in the waveform. Notice how the song has lots of changes from start to finish. If these peaks are not accurately controlled, this could result in an overly dynamic (unbalanced) listening experience.)


(This is a photo of the same mix from above but compressed and limited. Notice how the peaks are now consistent and the waveform overall is more consistent from start-to-finish. The application of compression and limiting reduces dynamic range in-exchange for setting a song to industry standard level (loudness) specifications. Although this example reduces much of the dynamic content and transients of the song, and in many cases is not preferred by mastering engineers; if proper use of compression and limiting is applied in a strategic way this can create a pleasing listening experience, while still meeting the controlled loudness demands of music distribution;  generally required by an artists record label, management team, or the artist themselves)


This was great back in the 1940s, but we are well over sixty years past that and the way we consume music is far different.

The way in which people listen to music has changed and because of that mastering must also change.

However, often mastering engineers are still viewed like they were in the 1940s, when in reality they are not.

Mastering engineers should no longer be viewed as strictly safety nets.

While they can be a safety net on some level, mastering is in need of some new PR.

How do we master now?


Much of modern mastering has fallen into a trap of creating identical works of art.

Presets and automasters have been created based on averages instead of serving each song individually as unique.

This has happened because mastering itself has been misunderstood for years and has not yet grown-up like other parts of the music creation process have.

While mastering has gone from vinyl to digital and now even back to vinyl, the mindset and approach for years has remained the same.

Many are still trying to apply the same mastering techniques that worked sixty years ago to an industry that has very much changed. We don’t have to throw the baby out with the bathwater, but we must recognize that mastering has been confused, blurred, and cheapened over the years.

While the current traditional view of mastering is to help create a similar listening experience from small cell phone speakers to high end speakers, we have missed the many other parts of mastering if that are the main focus.

It’s important to think about how a song or album may sound on a cell phone compared to how it may sound on studio monitors, but at the end of the day if we have learned anything in music, it’s still always about the song and the story.

Does it move us?

This is why we have albums that sonically sound “poor” compared to today’s standards that still outsell many of the new artists. Sonically, a lot of the older albums that are viewed as the “Greatest of All Time” sound inconsistent, they distort, they are imperfect, but yet we love them.

This does not mean we are chasing a “golden age” of music or the “good old days” but we can observe why we love those albums.

For most people, it’s because they are not sterile, flat or boring. They have character, they tell a story, they are not completely identically and because of that we are always discovering new things about them each time we listen.

They are human and on some level that always seems to impact us more.

Mastering demands the engineer to listen and analyze. Mastering at its core is about listening.

When mastering a song, an engineer might be thinking about the arrangement.


  • Do the choruses sound like choruses?
  • Do the vocals feel like they are in the right place?
  • Are there any parts of the song that sound so drastically different that it will totally distract the listener from understanding the point of the song?
  • Are those distractions there on purpose?


In order to even get these answers, a mastering engineer would benefit from talking with the client.

This is the first technique that should be used. Mastering requires a relationship with the client. Mastering is about communication and relationships.

It’s very difficult to master something when its viewed as a step that’s fully detached from the others.

We must not view mastering as a safety net as it was in the 1940s. We must evolve and progress in order to best serve the music in our current age.

How do we create masters that move us?


Mastering is about having proper relationships with clients and clear communication and expectations in order to hit the end goals.

Using mastering gear is limiting if you have no direction or guidelines on what the client is after.

A great mastering engineer will do the following:


  • Ask the client to send references songs to better understand the client’s preferences.
  • Ask the client where they would love for the mixes to be taken.
  • Educate the client in what is possible at the mastering stage based off of what the mastering engineer has heard.
  • Serve the work as a whole.
  • Enhance what is great about each song based on the end goals and tame anything that may get in the way off it based on what the client is looking for.
  • Leave all ego, pride, and bias at the front door of the studio.


These questions are a huge part of what mastering is.

If your mastering engineer is not interacting with you or connecting with you about these sorts of questions then your project is not getting properly mastered.

If there is no communication, then all the gear, monitors, software, and plugins mean nothing if there is no clear end goal or vision.

It would be really hard to travel across the country if you only had the city you want to arrive in as your only information. It would take you months to get somewhere that may only take a few days if you actually had some directions.

If the mastering engineer has no client connection or direction, then it’s hard to actually master something and best serve it.

Mastering is about a relationship between the engineer and the client first. Then, it’s between the engineer and the music. It’s a dance!

Mastering is about using tools only to help push the song towards the end goal that the client describes.

Mastering is about listening, communicating, and applying what is observed in a way that best serves the song.

Sometimes this is by repairing things. Sometimes this is by making things balanced from start to finish. Sometimes this is by using plugins and software that better handle modern material for digital consumption.

Whatever the mix and client is telling the mastering engineer to do should then dictate what should or should not be used.

Final thought


When we ask the question, “What is Mastering?”, we should get a new definition everytime, as each project is different.

Mastering can not be put into a box or viewed as just one thing, because it’s not. This is one of the reasons why great mastering is hard to find because it requires a wealth of knowledge and understanding that no two masters are the same.

Each project is different and each client is different. This then requires each master to be different.


The only thing we can truly land-on, which should be a universal principle for mastering, is always asking, “What will best serve the song?” The answer to this question will define “What Mastering Is?”