Expert TalkMusic Production

The Art Of Mastering – Expert talk with Libertree

The Art of Mastering – an interview with Libertree

Digital audio production allows for artists to home-record their songs at relatively low costs and, with the right knowledge, very high quality outcomes. Aside from the recording process, mixing your tracks yourself might be a good option, if you understand the principles of compression, EQ-ing, reverberation and the rules of dynamics. The more knowledge you gain, the better and there are countless tutorials and workshops available to foster your skills. But what about mastering? That final finishing process which rounds up your mixes and leverages them to industry standards with regards to loudness, frequencies and quality.

In the interview below, we talked with Berlin based musician, producer and mastering engineer Libertree about The Art Of Mastering!

Libertree, you are one of very few females in the engineering/mastering domain. Tell us, how did you become a mastering engineer and what makes this field so interesting to you?

Hey Katie, thank you for having me.

Well, I remember a few years back when I started releasing music and frankly didn’t know much about anything or myself. And there somehow I stumbled upon this blog article where the author was referring to mastering as „the dark arts“ that „nobody really understands“.

Obviously, I had to get involved afterwards. It was one of these „challenge accepted“ moments, you know. But all jokes aside, for me going into mastering was a process with different reasons behind it.

I am an artist myself, so when I started out I felt like learning and understanding some „music vocabulary“. It´s good to know how to properly communicate your vision with engineers and other musicians.

Later on, I wanted to understand what makes a good mix that is ready for mastering. Evaluating things from different angles always helps me with the process so looking at my mixes from the perspective of a mastering engineer made sense to me.

NOTE: There is a lot of crossover in the tools used by mixing and mastering engineers, with a couple key differences. During mixing you´re balancing individual instruments. During mastering, you´re balancing complete songs and spectral content.

Simply put, a mixing engineer makes instruments sound good together. A mastering engineer on the other hand takes the stereo mixdown and both corrects and enhances sonic elements to ensure optimal playback quality across all systems and formats before distribution.

Now I feel like I´ve developed a certain fascination for being able to shape music and feelings and eventually create an aesthetic that sounds like the stuff in my head. After all mastering feels like one piece of the puzzle to me.

In very few words, what is mastering all about essentially? What is the goal of mastering?

Mastering is the last stage every record goes through. We´ve all heard mixes that are finished but still sound thin and unfinished. That´s where the mastering engineer comes into the picture. The content of your song is set at this point and what mastering does is that it prepares your art for it´s final destination. If you are working on an album for example, you obviously want the songs to belong together. The whole album should have a coherent aesthetic and at the same time you want each song to sound good on its own and „on the same level“ as everything else out there.

So in short: Mastering prepares your music for Cd, Streaming Services, Vinyl, Video or Live. Every song is different though so the tools and enhancements vary a lot.

NOTE: If you want to know more about this, here´s an interesting article about the history of mastering:

The music business is probably 90% based on networking! Would you say being a woman in a male dominated field of business is challenging? Do you notice any advantages or disadvantages?

Mhm…well I´m to sure if it´s because I´m a women or because I am an artist but I feel like my approach to mastering is somewhat different to what I hear from other engineers. I don´t really believe in rules and actually do feel about mastering as an art while some people might say it´s more of a service that shouldn’t add any additional color. Both approaches make sense and are legit and what sounds better eventually is probably a question of taste.

When it comes to networking & gender I´ll have to say that in my opinion the music industry is challenging to everyone, one way or the other; And since I only have my own (female) perspective, I can´t really tell you if it was easier if I were a man. But sometimes I feel like there is not enough support for independent artists or maybe even artists in general as opposed to structures and old systems, but I wouldn’t pin it on gender. To be honest, my experience is that most people (male and female) think it´s kind of cool that I, as a woman, do also care and know about the technical side of music.

But yes you are right. There are very few women in this field. I hope that this changes in the future though because I actually do believe that mastering requires skills that women inherently have.


Percentages of women across three creative roles: 

21,7 % of artists are female

 12,5 % of songwriters are female

2,6 % of producers and engineers are female 

Read the full study HERE

I agree, that the music industry is tough for anyone! Alright, all gender roles aside, tell us a bit about the most important skills a mastering engineer must bring to the table?

That´s an interesting question. A he or she that mostly masters for major labels and therefore almost always works with A&Rs and not so much with the artists themselves will probably give you a totally different answer; But I´d say a pair of good ears, a diverse & well educated taste in music, a solution-oriented mind and lots of empathy.

As mentioned before I am an artist myself and in the past I´ve worked with mastering engineers that flat out told me that they don´t like my music or just didn’t really seem to care about putting their best efforts forward to understand what I was aiming at. Such insensitivities can be devastating and demotivating to artists and also harm the overall workflow on both sides.

After all, the artistic ego is a fragile thing so having empathy and a positive attitude towards other people, their art and perspective goes a long way in mastering I think.

When choosing the right mastering engineer for their projects, what should people watch out for/pay attention to?

You should look for someone that „speaks the same (musical) language“ and understands what you are hearing and where you want to go. I think that communication is quite important when it comes to mastering so you should look for someone that you like, that has a similar taste in music and a sound aesthetic that you find compelling.

When mastering tracks, what are the most prominent mistakes people tend to make in your opinion?

Honestly, I myself would never use the word mistake when it comes to art. I mean of course if your master is all distorted and muddy or if you can really hear the limiter then you might profit from a second opinion but besides that – everything goes. There are no rules. Everything for the song & vibe.

But if I had to pick a „mistake“ then I´d say „not being open minded enough“. There are actually songs and mixes that don´t really need much of a master or enhancement. Or sometimes they benefit in unexpected ways from an unorthodox approach. That´s what´s so amazing about this. There are no one-fits-all recipes and sometimes less is more. It´s all try and taste.

Then, what makes good mastering?

You feel it when you hear it.

Great answer! What is some of the equipment, any mastering engineer should have at hands? Something you can´t live without?

Good studio monitors. Or, let me rephrase: studio monitors and probably headphones that you know inside and out. Flying blind is never a good idea when it comes to mastering.

Note: I work with Mackie XR824 (Studio Monitors) and Beyerdynamic DT 770 Pro (Headphones). But that is a question of taste.

To refresh our minds, tell us, what requirements do radio stations have for songs to be played?

There are no standards. I mean for pitches I would use an MP3, simply because you can tag them (which you can´t properly do with WAV files) and maybe some additional information about yourself; If you prefer to send WAV files as well, you can use a service that enables you to connect different versions and formats of a song (e.g. DISCO).

But nobody really cares about the brightness of your song or how much compression you applied if that´s what you mean. It´s the same thing as with networking. People either connect with your music or they don´t. Obviously a good master can make a huge difference but I don´t think that any radio station will go like „if this song had a little bit more spread in the high end, then I´d play it“. So the only requirement is probably to only send your music to people that actually care. No mass emails or spam.

Note: WAV files are lossless and uncompressed which means they lose no quality from the original recording. The biggest difference is that MP3s are compressed audio and WAV files are uncompressed audio. Compression, in this context, is the process of reducing the size of an audio file.

People discuss the pros and cons of the loudness war. How do you look at this topic? 

I´d say that the loudness war is pretty much over since the streaming services started turning the loudness down (or up).

Let´s take Spotify for example. In their settings you get the option to play everything at it´s original loudness. I´ve tried it and it´s a cool feature if you prefer to listen to an album with it´s intended dynamics. But the moment you put on a playlist you will want to uncheck this.

So what Spotify and almost every other streaming service does now (to enhance the customer experience) is that they play all songs at the same perceived loudness by default. Which means if your song is a lot louder than everything else it will get turned down. Sometimes this can make your songs sound weaker and maybe even distorted. Nobody wants that. So I feel like most people master less „hot“ and more dynamic now.

But when talking about loudness it´s important to add that a loud master that gets turned down sounds super different than the same track mastered more quietly or dynamic; Because the processing is different. And sometimes the louder version is simply better with regards to energy and vibe. And sometimes the dynamic, quiet version feels more authentic. It all depends on the song.

So it is a multidimensional decision when it comes to loudness. I personally feel like every song or production has it´s own sweet spot and my job as a mastering engineer is to find and freeze that moment where the song unfolds and shines.

If you want to learn more about mastering music, I warmly recommend the „Are You Listening“ video series by Izotope. Click HERE.

NOTE: The loudness war (or loudness race) refers to the trend of increasing audio levels in recorded music, which reduces audio fidelity, and according to many critics, listener enjoyment.

In extreme cases, efforts to increase loudness can result in clipping and other audible distortion. Modern recordings that use extreme dynamic range compression and other measures to increase loudness therefore can sacrifice sound quality to loudness. The competitive escalation of loudness has led music fans and members of the musical press to refer to the affected albums as “victims of loudness war”. 

Great insights! Thank you! Last not least, how can people find you online?

You can find me and my work here:

Edit: I´m also curating playlists:

Thank you Katie & cheers.

Thank YOU! Best to you and all your future projects!