What is the difference between Mixing & Mastering?

What is the difference between Mixing & Mastering?

What is the difference between Mixing & Mastering?


Oct 22, 2019

I am asked quite often on how the two processes of mixing and mastering differ.  The technical discussions and various engineering aspects of outboard gear leave even the most experienced musicians, including myself, feeling at times confused.  I rely on not only my past experiences, but also my past working relationships with other producers and engineers, and on top of that I make sure to have a dedicated technical team that can help address any questions I have regarding the gear and its relationship to other gear & software in the studio.

It is I believe an art in dealing with the subtleties of sound design and how to accentuate certain elements in a mix for an intended effect – because of these aforementioned variables, there tends to be a lot of mystery leading to lots of misinformation – some people consider the mixing and mastering processes one and the same, or discard them as unnecessary if the music composition is good to start.

Having an educated and somewhat informed process to the different stages of the record creation process to the final stages of delivery to distribution is something that I want to help you all understand on this blog.

We will be proverbially “pulling back the curtain” to look at the five key differences between the two processes and I will humbly offer my personal insight into why they are important to the music that you write, make and listen to.

1)     The Studio Room Environment

To separate noises in a recording from something that is in an ambient or outside environment, mastering engineers work in treated rooms that are quiet.  Professional grade studios have acoustician drawings to get the mathematical formulas correct for the particular room environment that one may have.  Having the correct panel designs, the materials, everything has to be treated very scientifically, and for that, I refer always to experienced studio building acousticians before any gear has been placed into the room.

You need to hear the subtleties in a record, and as the mastering engineer is the last person in the creative process before distribution and replication – this particular work should be precise and not rely on guesswork from extraneous factors such as an inaccurate room.

To maintain a point of reference, engineers tend to stay put in one room they know well.  A modern pop album can explore hip hop, electronica styles, and sentimental blurry ballads – working within a room environment that is accurate ensures a level mixing and mastering approach.

2)  The Process and the Workflow

I certainly cannot speak for the process and workflow of other musicians, engineers and recording artists, and whilst there are some key differences in the approach between these disciplines, regardless of genre, there are also some bedrock foundations involved here across the board that apply in the professional recording world.  Because of the fact that mixers receive multiple tracks, a chunk of their job, at least in the earliest stage, is organizational in nature – labelling and coding tracks, ordering them by subsections or by hierarchical necessities in a DAW, creating instrument layers or stacking / bussing routes etc.

Once this is done, I will generally proceed to then have everything lined up and begin creative tasks such as stereo plate reverb outboard passes, filtering, transient shaping, artifact cleaning up, effects automation, stacking or levelling out – any process which can be defined by allowing the separate tracks in a song to blend well together.  Think of mixing and mastering a record like baking a cake – there is no right or wrong way but you have to be respectful of the way the gear operates and how your ears react to what you are hearing whilst working.

Depending on how a production sounds when it reaches the mixing and mastering engineer, a full song mix can take anywhere from a couple hours to days depending on the level of invasiveness.  I have personally had projects which contained over 150 multitrack stems in 24 bit 48K = LOTS OF FILES.  You have to be extremely organized on projects like this as it can go through many iterations depending on the artist or the label wishes.   I have always relied on building long term working relationships with my artists and label clients, and multiple versions are normal in the scope of creating goodwill and polishing the final diamond.

This time investment requires that mixing and mastering engineers develop a routine to maintain focus and avoid ear fatigue.  Personally I love to start working on a mix with melodic or instrumental elements, and then work in percussion and low end accordingly after.  The blend is ever tweaking the mix to achieve the most vibrant and vivacious sound you can without overdoing it.  The subtleties is what defines a good mixing and mastering engineer to a great one.

When it comes to the mastering stage of a record organization is also key, but my focus here is narrower.  The mix and sound design from the composition itself already define the record, and the final mastering gloss is for me to apply sparingly – the fine balance between making it as loud as possible whilst still retaining a LOT of depth, dimension and organic texture.  Being comfortable with your outboard gear and software tools is essential here – as well as being able to have comfort in using your tools sparingly for maximum effect.

Even though the creative changes that happen during the mastering stage are more subtle than those are the mixing stage, there will still be unexpected consequences that need to be listened and watched for.  Remember that changing anything in the mix fundamentally affects the perception of the overall mix itself.

Lastly, multiple ears are great for objectivity.  Personally I make sure to have a couple different mastering passes and then to listen later to find which pass was best – subtleties are nice to compare against before deciding your final pass for distribution.

3)  A Rough Overview Of Tasks Associated With The Mixing & Mastering Process

It is nice to roughly distinguish for those of you learning about these different processes some of the tasks associated with mixing and mastering.

Mixing is the start of the post production process – where an engineer like myself carves and balances the separate tracks in a record with as much power and vivaciousness when played all together.  With various outboard and software tools like EQ, compression, panning, reverb, etc. – mixing engineers reduce harmonic & frequency clashes between instruments, as well as tightening grooves, stabilizing certain audio dips, and emphasizing important elements in a song.

In many cases I have been asked to even layer drum hits with samples from outside the session or mute redundant instrument parts once the client has heard a cleaned up V1 outboard pass of the mix.  Things get accented and the project morphs as you chisel away to what you want to hear in the mix itself.

4)   Respecting the Creative Process Of The Record Itself

Mixing and mastering engineers also need to respect the creative process and communication with their artists and clients is key – MANY TIMES mixing decisions serve the arc of a song, which may be communicated explicitly by an artist or understood by the mixer based on experience.  The chorus always needs to hit hard – this is a maxim for pop music.  The kick / bass relationship always has to be perfect for any club record – this is a maxim for instrumental club music.  On a ballad the vocals always need to sit in the front of a mix – this is a maxim for this style of music.  These rules are learned over time and experience and there are millions more rules, for which could suffice in a book format.  For now I just wanted to give a nice overview of these different stages and processes.

A mastering engineer takes the stereo mixdown and both corrects / enhances sonic elements to provide a sense of vivacity and clarity to the final record.  It needs to ensure as well that there will be optimal playback quality across all systems and formats before distribution.  Mastering is balance the art of the impossible – requiring an attentiveness and experience that no other person in the music making process has – it is the last chance to make a change to the way the record fundamentally sounds, and to catch any sonic mistakes that have come along the way through the creative process.  All decisions made at this stage are what appears on all copies and duplications of the song.  It is also extremely normal and encouraged frankly, to have different masters for digital and vinyl if you are also getting your music put onto a physical format.

Lastly, once a song is finished by a producer, it is handed off to a mix engineer as a full session or by what I prefer – multitrack stems.  It could be a small session or a large one, the level of invasiveness dictates the price because of the time involved.  As well as the number of passes being run on.  Mastering engineers make final touches to a project from the bounced mix version of the record – the restriction of this file format is part of what makes the mix phase defined by its usefulness – there is only so much that can be done with a stereo recording.  At the mastering stage we cannot go into a project to sculpt a kick drum, filter a synth, or automate/unmask vocal parts – our role here is to make subtle adjustments and enhancements to the entire mix, keeping in mind the artist’s vision and market standards.

5)   The Various Tools Used In A Professional Mixing and Mastering Studio

It took me many years to save up for the various outboard gear tools that I needed for the quality that I wanted to provide for my artists and label clients.  There is thankfully a lot of crossover tools today which are affordable for those starting out, and for those who have wanted to dive down the rabbit hole in what various creative minds have designed for studio tools and applications – it is an addiction which constantly grows.  For me I personally prefer to have less gear and know each piece 110%, rather than have 100 pieces and knowing them 20%.

In the ABOUT US section you can see my various outboard gear and software tools used – I am humbled to say that I am sponsored by many of the most forward thinking companies on the planet, such as Shadow Hills Industries, Manley Laboratories, Chandler, Eventide, Bricaste, and many others.

Taking the time to learn how each piece affects sound is the most important aspect of the mixing and mastering engineer – in laymans terms – understand your toolbox, and learn how to use them in ways that are creative but also aren’t so obvious.  People want to become emotionally attached to a record and your job is to actualize that by way of good mixing and mastering techniques, whether creative or scientific.  However you get the job done is what defines you and your resume / work.

One of the most important tools to mastering is a limiter – being used to bring loudness levels and RMS level standards – louder is not better, though it should be within the roughly defined ballpark of a similar musical project or genre.  Essentially a compressor with a fluctuating 8-15:1 ratio, limiters are a safeguard placed at the very end stage of a mastering chain to catch the peak moments in a song as input gain is increased. This process allows the engineers and myself to boost the quieter parts without pushing the highest peaks into distortion – again this is a very delicate balance and takes time and years of experience – after over 12 years myself I am still learning and that is how this process should be – always an ever learning process that can be refined and tweaked over time.  The wonderful thing too about technology getting better is the options available when creating and processing music.

As well, if you ever have any questions relating to the mixing or mastering process, please feel free to contact me and fill out the Contact Form of the Alpine Mastering studio website.  My name is Glenn Morrison and I am really thankful that you expressed an interest in what I do, and reading my blog here on the concepts behind mixing and mastering.