WHAT IS AUDIO MASTERING?

Hi Guys & Girls 

As a Mastering Engineer at Studios 301 I have been asked many of times over the years these very questions.

- What Is Audio Mastering?

- Why Do I Need To Master My Mixes?

- Will The Mastering Process Help My Music?

Let me start with “What is Mastering” and this will help answer the next two questions. The Mastering Process has changed a lot over the years thanks to the advances in technology & computers. Traditionally the Mastering process was only a transfer stage. Once all the songs were recorded & mixed to the artist, mix engineer & producer’s liking, only then was the mastering engineer brought into the picture and his or her job was to make sure all the songs (mixes) stayed true to the musical style & consistent through out the Album, or now days CD’s, on any play back medium. Now the Mastering process can involve Stem mixing, adding sound FX, multi-track editing and even the occasional overdub recording. Yes mastering has come a long way but the fundamentals remain the same, this is because it’s still the last stage in the music making process before it goes to manufacturing and the CD’s are made and that means it’s the last chance to make any changes before your CD’s are pressed and the public gets to hear it.

So, what is Mastering? Firstly let me explain why consistence on a CD is so important before I get into how it’s achieved and why it’s necessary. As an engineer it’s very important to keep the listener in mind, because at the end of the day it’s the listener that will disced if the music is worth listening too and ultimately if it’s worth paying for. The last thing we all want as listeners, and fans of music, is to pay good money for a CD only to be disappointed by the experience because some songs on the CD are too loud or to soft in level in comparison to the other songs on the CD. Another example is if some of the songs are to bright (to much high frequencies) or to muffled (not enough high frequencies or too much low frequencies). I’m sure you’ve experienced this at some stage, this is what you would call a poorly mastered CD because the whole listening experience is interpreted by contently adjusting the volume level on the stereo, instead of kicking back and enjoying the music.

Consistency on an album/CD is crucial to the listeners enjoyment and hence the success of the CD/Album. You’re probably wondering why the mixing engineer is not responsible for this and the simple answer is, It’s not the mixing engineers fault or job to worry about this. Of cause a great mixing engineer will always keep the big picture in mind but at the end of the day the mixing engineer’s job is to get a great balance of all the instruments and the effects and this is time consuming enough. Also there are variables that are out of mixing engineers hands, for example there might be more than one mixing engineer working on an album and they might even be working in different studios, this will automatically give the songs a different sound. Another reason is the songs might have been recorded & mixed over a long period of time over many months or even years, in different studios with different equipment. This will also give the mixes a different tonal sound along with different mix levels. This is a very general and simple explanation but hopefully it’s explained why the consistency of ALL the mixes on a CD is important and why the mastering process is carried out after the mixing stage is finished.

As for how this consistency is achieved by a mastering engineer is another story all together. Let me start with a simple explaining of the mastering process. Mastering all the mixes for a CD is a lot like balancing/mixing all the instruments in a song. By this I mean when you’re mixing a song, your focus is on balancing all the instruments and effects so that they sit in their rightful place in the stereo image & no two instruments are clashing together tonally or level wise. For example the vocals are clear & are not getting lost or drowned out by the guitars or keyboards, the kick drum & bass guitar are working together to create a solid grove, the overall drum kit is balanced right and the hi hats & cymbals are not louder or brighter then the snare drum, the kick drum or the rest of the percussion instruments.

When Mastering a CD these same principles apply, the only deference is the mastering engineer is balancing 10 to 15 mixes, not instruments and all the songs have to “sound” & “feel” like they all belong together on the one CD.  This process is achieved by using tone controls (Equalisation) and level or dynamic controls (Compression & Limiting).

For the purpose of this article I will keep the explanations simple and brief, only because you can literally fill books explaining all the different scenarios, tools and technics that a mastering engineer has at their disposal to achieve the out comes necessary depending on styles & genres of music, And these topic will be covered in later articles.

Let me start by explaining why & when equalization (EQ) is required. 8 out 10 times it’s the bass frequencies that need the first attention and again this is for various reasons, for example the monitoring in the mixing room might not of given the mixing engineer a true representation of the low end, therefore there is to either too much low frequencies or not enough. This is where the EQ’s come in, and I say “EQ’s” because that’s exactly what it takes. Different EQ makes & models work best for different application, “horse for causes” for example if the low end of the mix had a good balance, Kick & Bass are siting well, and it’s just a matter of adding or taking out overall low frequencies, then one would use a nice broad band EQ (by Broad band a mean an EQ that covers a large frequency band). This will keep the kick and bass balanced in tacked and only affect the overall low frequency level. On the other hand if there is too much of one or more particular frequencies but the overall low-end level is good then one would use a notch filter or an EQ with a very narrow frequency band so you’re only affecting a very small area of the sound field.

Once the bass frequencies are looked at and adjusted the rest of the image usually comes to life and then it’s just a matter of fine tuning any high or mid band frequencies, again this happens for different reasons. For example the speakers that were used during mixing might have been too bright, this would be giving the mixing engineer the illusion that the top end (High frequencies) level was right in the mixing room but as soon as the mix was played out side the mixing room, like in the car or at home in the stereo, the mix will sound like it’s lacking top end and feel very dull. Vis versa if the speakers in the mixing environment were not bright enough then the opposite would happen; the mixes would come out sounding too bright. This is were the mastering engineer comes in and will adjust the mix accordingly by adding or taking high frequencies out.

Like I said this is a very simple explanation but you get the idea and hopefully you can see why it’s very important to focus on the balance of the instruments & effects when mixing and not be concerned about how loud the mix is. If you focus on the internal balance of your mix it’s very easy then to adjust things accordingly at the mastering stage and you will end up with a great sounding, and loud CD. If the balance is not right in the mix and for example the shakers are louder then the Hi Hats, this makes the mastering engineer’s task very difficult and time consuming.

This brings us to Compression & limiting. As I mentioned before don’t be too concerned about the overall level and loudness of your mixes, this is one thing that is best left to the mastering engineer. This is because it’s a much easier to work out exactly how much compression & limiting all the mixes require when you can hear all the songs together after the mixing stage is over, and only then work out how much compression & limiting is required for the entire CD, so that it sounds natural consistent and dynamic. Always remember that the more you compress or limit a mix the less dynamic range you’ll end up with and this is one process that can’t be undone.

If a mix is too bright it can be fix with some EQ BUT, if a mix is too compressed or limited you can’t fix this in mastering and you can’t put back the dynamic range or all the transients of the snare & kick drum which gives you all the punch & excitement that makes a song come to life.

I don’t mean to scare you or turn you off compressing & limiting your stereo mixes, these are very handy tools in the right hands, but in the wrong hands they could potentially ruin your mix and all your hard work. The best advice I can give you after seeing people make this same mistake over time is make two versions of your stereo mix. Bounce one version of your mix without any stereo bus compression & limiting and one version with stereo bus compression & limiting. I say this for three reasons, the first reason is if you bounce a stereo mix without any compression & limiting, you’ll have a nice dynamic stereo mix that you can take to the mastering session and once the mastering process is finished you’ll end up with a great sounding song with lots of punch & clarity. The second reason is doing a bounce with the stereo bus compression & limiting on will give you a good idea of what to expect from the final mastering session. The way the dynamics, the bass and the general balance is affected and if need be make any changes to the mix accordingly. And the third reason is when you play your mixes to other people, playing them the compressed & limited bounces of your mix will sound a bit more exciting then the uncompressed & limited version and we all know “first impressions are lasting impressions”, especially if that person is someone you need to impress like A&R, management & a booking agent.

Don’t worry if your not sure about how to set up a compressor correctly, or a limiter or even an EQ. We will be covering all these topics and more in great detail in articles to come. Like I mentioned earlier this is the first of many articles and we’ll be covering a whole range of issues to help you become better at your craft. If there are any topics you’d us to cover or if you have any questions, do hesitate to contact us at studios 301 and we will be more than happy to give you some info and help you out.

Thanks for your time and I hope all this information helps you become a better musician, engineer and producer. Until next time I wish you much success with your music don’t forget to have fun, it’s very important for your health!

Chio for now.