What is Mastering

With the liberalization of music-making, I've started seeing a trend for artists and engineers to take on more roles during the production of a track, EP, or album. It is not uncommon for artists to engineer large portions of the album, for the engineers to mix and even master, and for mixing engineers to deliver a master for every mix they turn.

More hobbyists and semi-pro artists can record and release their creations often, with very decent quality. This is achievable at the comfort of one's home and with affordable equipment. This new reality pushes the budgets down for recordings and other services for the semi-pro and hobbyist circles. And when a 3rd party is required for those projects, not only the budgets are low and the competition is high! Artists try to do as much as they can themselves to save money, engineers try to offer as much value as they can to make themselves competitive. A mixing engineer can easily add mastering to his or her services to make themselves more competitive against other mixing engineers that do not.

At the turn of the Millenium, we saw a fierce race in the loudness wars. And, at the same time, the bulk of the music sales shifted to digital - making several of the hard-mediums obsolete. The more traditional role of a mastering engineer had somewhat lost the importance it once had. It became about making things loud, and into an MP3 or YouTube video.

And, in recent years, to make things even more confusing, several online "mastering services based on some AI or machine learning technology" create further confusion for upcoming artists and engineers.

But we, in 2020, are at a crossroads. All the major online media platforms are unifying against loudness wars and slowly moving towards a standard.  
They listened to the listener's complaints and decided enough was enough - a repeatable standard for sound playback was necessary for the viewers' comfort. No more "remote control riding" the volume as you flick through different series or movies.

As a mixing and mastering engineer, it's my job to keep up to date and understand what these changes are. What they mean for the music I mix and master.  
And perhaps more importantly - what this means to the goals of the artists I work with. This is a conversation I'm having more and more often with my clients - what are your distributions goals with this track?

In this article I'll cover the classic definition of a mastering engineer, and how it differs from the interplay between mixing and mastering engineers as I experience them in 2020. 
What I look for in a mastering engineer in 2020 and why do mastering studios and engineers have specialized gear, studios, and workflows.

What exactly is a mastering engineer?

Historically, a mastering engineer was a transfer engineer. They would transfer your final mixes to Vynil, Tape, CD. Not only they knew the requirements of a Glass Master or Wax Master, they knew how to use the tools available (EQ, Limiting, Compression) on a mono or stereo file to maximize the mix for the medium they were transferring it on. As time progressed, mastering engineers became skilled at identifying what makes a song translate well in most playback systems - i.e. what makes a song play well in most systems mediums. The mastering engineer has become the ultimate QA person in the production chain, and an indispensable part of it.

As the years go by, mastering engineers started to require the best reproduction systems in the best acoustically tuned rooms to be able to listen - with the best equipment possible - to your mixes. They were able to make informed decisions about the track, and perform small fine adjustments. As mastering techniques developed, the best mastering engineers became able to truly polish and enhance a track to sound bigger, cleaner, wider, punchier, louder, etc.

This is not all! Although is true almost all artists (and even mixing engineers) seem to be fascinated by the mastering engineer ability to EQ or compress a song to make it sound better, but we all often forget about the mastering engineer crucial roles on your albums and EPs:

• To level balance the songs so they match in the context of an album
• To EQ balance the songs so they match.
• To sort out fade in and fade out of each track.
• To sort out the space between songs so that your album flows well
• To generate RedBook PQ Sheets or DDP masters.
• To ensure the mastering meets requirements for all platforms
• To print the medium for required platforms.

"Prints the medium for required platforms." 
Feels like such a simple statement - Just bounce your mix down to a ".mp3" or ".wav" right? We'll look in a bit why this last step is so important again in 2020 as streaming platforms are introducing tighter and tighter requirements.

 

Mixing engineers and mastering

I believe that a good mixing engineer knows or at the very least understands the mastering process. I would never call myself a mastering engineer, but I am aware of many of the techniques used, I have a reproduction system that is adequate to make a number of decisions on, and have mastered commercially available songs, EPs and entire albums.

But I always recommend that my mixes should be sent to a mastering engineer.

Most of my clients - and I believe this to be a widespread behavior - only worry about how loud their song is and how good it sounds. Virtually all my clients only have digital distribution in mind - YouTube, Spotify, Bandcamp, and social media platforms. Anyone can put up content on these platforms. In fact, up until a few years ago, there were virtually no requirements on any of these platforms. Mixing engineers could try their hand at mastering and a lot of them could get away with really good results.

For me, the warning signs started when a lot of engineers who established themselves during this period believe this is their sole purpose - to make things loud!  

In my opinion, this couldn't be more wrong.

 

Why does my kick sound weird? And the vocal is all sibilant?

Another reason why I believe it's fundamental for mixing engineers to have a basic understanding of mastering techniques is to understand what it'll do to their mixes. This is why I've started applying mastering chains to all my mixes, to understand if - during mastering - any balance decisions could be affected. If it would drastically change any transients, or if it would create harshness or even bring on sibilance on main vocals.

 

In my early mixes I've made this mistake more than once - sending mixes to mastering that would come back brighter (sometimes harsher), losing punch, or to see the mix "buckle" and the balance falling apart under more severe compression and loudness maximization.

What do I look for in a mastering engineer?

I want my mastering engineer to be an extra set of ears to the project.  
In fact, if I don't hear any kind of comment - positive or negative - I worry about the quality control front. I've had both "Wow, this was a great mix, didn't have to do anything to it" and "Hey mate, can you do a few revisions for me? This mix has quite a few problems". And that's ok - that's what I expect from a fresh pair of experienced ears.

Next, I expect the engineer to line up all the audio and make it into an album - set the spaces, fades in, fades out - and use their EQ and dynamic control tools to make them all fit aesthetically on the same album - in addition, to fix any issues or add any improvements that will make the track play better on virtually any device.

And - then and only then - make it loud AND up to spec. We might decide to ditch the spec because we want the aesthetic of a more compressed album as in the last single I've just received from mastering, or we might decide to keep to the spec because we want an album with dynamics, clear sound, and no artifacts from limiters/compressions.

 

I had a client come to me for advice on their latest master. It was turned up so loud that it had -1dB LUFS range. I think this pretty much means the loudness war has been won, no? Anyway, the downside was that this was going to be mainly released on youtube. Who promptly brought the track down -14dB. IT WAS ONE THE QUIETEST VIDEO I'VE EVER HEARD ON YOUTUBE. The client was distraught, upset, and lost. The mixing engineer - who was also the mastering engineer - could not see the issue and admitted to being unaware of specs for streaming. After conversing with the artist, he liked the aesthetic of the really loud master as the distortion and brick wall fit the genre of music. My advice was that he had tried to negotiate with the mixing engineer 2 deliverables - a slightly backed off version of the current master (let's call that one the master for CD) and a mastering closer to the specs for streaming so it wouldn't be penalized so harshly. And, if he had the budget, to try and get the original mix remastered (for CD and Streaming) by a versed mastering engineer.

 

Mastering to vinyl is now way more lenient than it used to be, but it's still the perfect example for my earlier comment: mastering is and always has been about preparing delivery for the medium - and vinyl was the most demanding medium to prepare for. A bad master that is not prepared for vinyl can result in really bad translations and even destroy the cutting equipment (in reality, the operator will just turn the audio down and protect the equipment first).

 

What do you have against loud music?

Nothing! 
I'm a metalhead. The music I choose to listen to is probably some of the loudest, most compressed stuff on the planet.  
And I'm the first one to say it would not sound good without the heavy amount of compression and limiting techniques used to make it that loud. It's all a part of the sound and the aesthetic.

But there are other genres out there that would be better off without these loud masters.

I stopped debating loudness wars. They exist and I acknowledge the loudness war is a thing and needs to be considered. 
But, with my clients, I now always talk about it as a balance of aesthetic vs competitiveness. Balance of audio fidelity, punchiness, and dynamic range, vs. being able to compete or fit in a playlist alongside other artists.

 

Just yesterday my mastering engineer sent back a brilliant master sitting at -13.5dB LUFS, pretty much close to spec of Spotify and YouTube. As it was a Pop tune, myself, the producer and the client had to sit and consider that we might want to abandon the spec to get an edgier master that could sit alongside other similar bands. Our v2 master was a hot master for comparison, and we had to weight the compromises within losing some clarity on the mix, added distortion, and less punch for a competitive track. We went with the later.

 

Mastering gear and why it differs?

Can I master with the same tools I use for mixing? Sure! I can pull it off! 
But then why do mastering engineers have different gear - really expensive gear - and why is it such a big deal?

Starting in the analog realm, mastering grade equipment is made to a higher spec. They are usually made with less noise (essential if you are going to provide a lot of gain and reduce the dynamic range), and higher headroom. They are also made with extremely low tolerance parts so the left and right channels are as matched as it can be. Mixing gear can sound wildly different from channel to channel and even from the left and right channel on the same stereo unit. Even in high-end mixing gear, if you line up the potentiometers to do a 3dB cut at 1kHz, you might find that the frequency could be as off as 50Hz on each channel, and a dB higher or lower than what you aimed the controls at. Finally, mastering gear uses stepped controls with finer ranges than mixing gear (while mixing gear might have 2dB gain steps, mastering engineer will have smaller steps of 0.5dB) for precise control and easy recall ability.

Moving to the digital realm, not all DAW are suited for mastering duties. Some are a "one-stop-solution" for mastering which makes workflow nicer. As for plugins, some of the same considerations apply as the analog gear realm. Plugins that are geared towards mastering usually have less distortion, noise (in the case of analog gear emulations), and will use several DSP tricks under the hood like anti-aliasing, over-sampling, and linear phase response to minimize the introduction of any artifact from digital processing.

The tradeoff here is CPU power and bounce times. You probably wouldn't want to have 15 limiters running at 64x Oversampling with anti-aliasing if you are bouncing a mix as that would probably take you a few times longer than the duration of the song (depending on the number of threads on your CPU). In plain English, it would make your mix bounce down to take an eternity and a day, and it would tax your CPU heavily. But when mastering, you'll only be using a couple of instances of those plugins and that is far more manageable.

 

Step into my living room, erm, mastering studio!

And finally, the rooms! Why do mastering studios sometimes look like an audiophile's living room? 
Because they want the best acoustic environment possible to make decisions on your masters. Mixing rooms traditionally housed a large mixing console and a ton of outboard, large window panes, and computer screens. 
All of these are notoriously bad for acoustics. And mastering engineers do not need them to carry out their work.

This is especially true for mixing consoles and desks/workstations. They are notoriously bad for acoustics. They introduce a series of short reflections that cause extreme comb-filtering. People who are not used to sit by a console can make quite a few errors when EQing elements of a mix. During the years, manufacturers tried to minimize the acoustic impact of mixing consoles but there's still some. By eliminating mixing consoles, workstations, or computer desks - and in fact anything between the engineer and the speakers - there's less acoustic issues for one to worry about.

Mastering engineers are also not dealing with artists across the glass, so the mastering room can be designed for optimal listening acoustics.

But you will still find a lot of award-winning mastering engineers who use desktop workstations, rooms full of gear, or those who do their work in a small spare bedroom.

And finally, patch bays. A thing to avoid.  
When it comes to noise, distortion, and unreliable connections, patch bays are a thing to avoid. Most mastering studios like to use either custom consoles, digitally controlled electronic patch bays, or specialized mastering consoles - that use electronic switching (relays) for changes in routing. This means no degradation from cables, jack plugs, and patch bays. Trust me on this: patch bays are always a source for noise and weird degradation to your signals.

If you are interested in looking more at solutions for mastering studios, have a look at the Maselec, Crookwood, Manley, Dutch Audio, Dangerous Music, Weiss, Elysia, Shadow Hills product range to have an idea of the features offered.

Final notes

As the industry changes, the classic roles involved in audio production have become more fluid and now interlap with each other.  
But we audio professionals still need to understand the specifications of the target media we are preparing our audio for, and it's our job to keep clients' goals in mind when we prepare their final deliverables.

Mixing engineers should be familiar with mastering techniques and even attempt to do it themselves, but whenever possible, delegate to an experienced mastering engineer. This will make mixes translate better and avoid any surprises that can occur from the mastering process.

The value added by having an experienced, fresh pair of ears in a project is invaluable. And the experience the mastering engineer can bring - who prepares media for Spotify or YouTube or Vinyl day in and day out - is invaluable.

In 2020 and in the future, as platforms keep tweaking their specs, having separate masters as deliverables are going to become less than an afterthought, and more of a requirement. Although, in the present day, as most of the work I'm part of is meant for digital media platforms, their specs are so close together that we can happily find a good compromise for all platforms in a single deliverable.