Dispelling the myths surrounding audio mastering
March 28, 2013
Barry Gardner in mastering

Being a mastering engineer allows me to explain some of the common misconceptions that surround this important final music production process. Whilst mastering has become a somewhat expanded service over the last decade there seems to be some online confusion as to what audio mastering is capable of and what constitutes a professional mastering job. We are going to look into some of the misconceptions surrounding audio mastering in order to get a clearer understanding.


The goal of mastering is to holistically correct and enhance a set of tracks that are destined for release. This usually involves equalization, dynamic range compression, adjustments to stereo width etc. Quality control of the end product is also important, listening for clicks, glitches, bad edits, pops and other extraneous noises that may have gone unnoticed during mixing. Additionally it includes adding subcodes such as CD-TEXT, ISRC codes, artist and track names and musically sympathetic spacing of the tracks on the release medium.

With this brief outline of what mastering involves we can dispel some of the wrongly held beliefs related to mastering audio.  



Mastering is just adding a limiter to my DAW (digital audio workstation) output


Nothing could be further from the truth, a limiter is an extreme audio process and they are to be used with care. Typically a mastering engineer will be considering many factors regarding the quality of a music mix. Limiting it is simply one of them certainly not of greater importance than any other factor. Limiting is interdependent on any preceding audio processing, be it analogue or digital. Limiting is merely 1 tool which is used to increase the perceived volume of a track and most professional mastering engineers do not solely leave it to the limiter for ‘loudness making’.  Additionally a mastering engineer normally has a variety of limiters for mastering because they all sound different to each other. This way limiters can be tailored to the job at hand. In my own work I often try any of the 5 mastering limiters I own because each one can tonally affect the track in either positive or negative ways.


 
Mastering can turn a bad music mix into a good mix


A bad mix will almost always remain so. It is vital that the mixes produced and sent for mastering are the absolute best mixes that are possible to create. That means getting the tone and instrumental balance spot on before sending out for mastering.


In mastering there is only very slight control over being able to adjust the level of specific mix elements discretely. There are ways of manipulating or trying to isolate specific instruments but this is normally a compromise as it is often difficult to do without affecting other mix elements. In these instances a good mastering engineer will communicate with the client and offer practical and useful advice on how to correct any mix issues before proceeding further. In fact this is one of the expanded services that some mastering studios offer.   


 
Mixes will always come back sounding fuller and fatter sounding


This will very much depend on the mix itself. Mastering is concerned with translation of music. This means the mastering engineer will aim for a final result which has the best chance of satisfying the largest number of listeners across the widest number of play back systems. A bass and low mid heavy / harmonically rich sound might sound great on a small set of multimedia speakers but could easily sound terrible on a large bass heavy PA system with analogue overload limiters employed. Any extreme deviation from the optimal tonal balance for a given genre could mean there will be translation problems. So a mastering engineer will listen to music on a very familiar music reproduction system and within seconds know that there is too much bass or a bloated muddy mid range and will correct the music accordingly.


 
Music mixes will always come back sounding bright and sparkly


This is also dependent on the mix balance. An overly bright mix will most likely have the top end subdued rather that enhanced so unless you are already confident of your mixes tonal accuracy then be open minded about the results received back from the engineer. One common issue is a tonal mis match between mix elements that hinders optimal fidelity and translation. An example could be high hats that have lots of energy above 10kHz and a vocal that is dull and lacking in presence and air. This creates a challenge during mastering and a diligent mastering engineer will communicate such issues and ask if this is an intentional production goal or if something has been misjudged. It will not be possible to enhance the highs on the hi hats without negatively affecting the vocal. If the opposite was true and the vocal was bright and the hi hats dull  we have a similar issue. Communicating such aural observations is important in order to get the best results.  



Professional mastering can be performed at home


The objectivity and experience of the mastering engineer is very important to the end results. This experience can often be incorrectly discounted by the inexperienced purely by thinking good plug ins are now available. Mastering requires accuracy before even a single adjustment to any aspect of the audio is made. Without sonic accuracy and a mental reference bank of how various musical genres should sound there is little basis for adjustments. (Accuracy includes full audible spectrum monitoring, accurate transient reproduction, stereo imaging, tonal response of room (acoustics) and low distortion monitors and amplifiers) Most mastering rooms are set up with ultimate fidelity and accuracy in mind. Once the room has been treated and set up for accuracy the engineer will not change the position of equipment or acoustic so the rooms sound character becomes second nature and a true reference. From this understanding tonal issues in music mixes jump out in a very obvious manner and the mastering engineer will be able to correct and enhance the music. It is exceptionally rare to find these conditions in a home or project studio environment. Even top end professional studios have their output mastered before release.



Professional mastering can only cost $10.00


This is extremely unlikely, the costs involved in equipping and designing a mastering studio mean that such rates would not create a sustainable business. The man hours spent in learning the craft of audio engineering is a considerable time and money investment and any professional mastering engineer would be unable to charge such low rates. Most serious mastering engineers have worked professionally in various types of audio facility and have been professionally trained by highly qualified engineers who have mentored them throughout their developing career.



Professional mastering can be done with 1 multi module ‘mastering plug in’


A mastering engineer given one plug in with multiple modules could probably make a decent job of mastering a track given the room and monitors that they normally work in. However this does not mean that the best master could be made. Most mastering studios have both analogue and digital options for at least equlaization and compression. High end analogue equipment often produces results which are greater than their individual parts. An analogue chain is an interdependent and almost ‘alive’ set of equipment. Each device subtly influencing the next in the chain. Analogue mastering equipment often has secondary and euphonic characters over and above the primary use. For example a specific eq may be able to smooth transients and round a sound out before any equalization curves are dialed in. Or a compressor may be able to add a subtle sense of air and openness and a slight bass boost before it even goes into gain reduction. All of these small carefully selected enhancements add up and this is where the so called ‘magic’ of mastering can materialize.   



Mastering is a dark art or mysterious


It can appear that way but with experience, sonic accuracy and exceptional equipment it is about knowing what needs to be done in order to produce the best results. This can appear elusive to some because they discount the experience of the engineer and subsequent ability to make the right judgements. This judgement can also be extended to making the correct choice of mastering grade audio equipment.  



Mastering can be seen as part of mixing


The objectivity of fresh ears and the style of listening means that is very different to mixing music. The limitations of working with stereo 2 track mixes means that the engineer will listen in a different way than a mix engineer who has the luxury of being able to eq, compress and level each individual musical instrument in the mix. Mastering has a different approach and cannot be compared with mixing. It also has different goals, one obvious one being trying to bring disparate tracks together in a subjectively acceptable and furthermore pleasing manner.



Mixing engineers can do mastering  


A mixing engineer cannot normally provide the objectivity to master a project if they mixed it themselves. Any deficiency in monitoring can mean mastering on the same environment and speakers can be compounded and unheard issues be worsened. Professional mixing engineers are very skilled individuals, they are likely to have undergone similar training for years on end as a mastering engineer but specialize in musical balance on a track by track basis. Top mixing engineers with 20 years or so of experience still have their music mastered before release, this in itself cements the value of mastering and normally the less experienced engineers consider themselves capable of mastering the mixes they have produced.



Summary


Mastering has definitely evolved over the years and often includes feedback to producers, bands, engineers and record labels on music mix downs that are supplied. As the industy contuinues to evolve mastering must also evolve and as such provide a more encompassing service than just transfer to final medium for release. Whilst this is the case it is important as a musician to understand what mastering is and it’s strenths so you can obtain the best results and make better decisions for your own musical releases.

A post from mastering engineer Barry Garder who operates SafeandSound music mastering

Article originally appeared on Music Think Tank (https://www.musicthinktank.com/).
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