Mastering – Understand once for all what it is and why you need it

Whether you're planning to play your music on a stereo, on cellphones, or on radio, mastering will always be key and you should really care about it. There are plenty of articles on the internet about the topic, but do you really understand what it is and what is it for? When it comes to such a delicate process there are lots of things to consider, like tools, the steps of the process, your objective... So today we're going to look deeper into it and I'll help you understand once for all what it is and why you need it.

What is mastering?

In a previous article, you've learned what's the difference from mixing to mastering. Today we're going to dig deeper into the mastering topic. So, what does the mastering process do? You can say that it is meant to optimize the overall sound. While mixing refers to the process of putting multiple layers of audio together to make one final track, mastering should add a final "glow" to your music. It consists of optimizing each individual track by equalizing, compressing, making stereo enhancements, or adjusting the reverberation (echo) effect.

Where did the term "mastering" come from?

You ever wondered where did the term come from? Basically, it comes from the idea of a master copy. All copies or duplications of the audio come from the master. It goes back to the era of vinyl's discs, do you remember those? The matrix, or in other words the original copy, was made from a very resistant material, which will be used as a reference for grooving (cutting the furrow of) the copies.

How does the mastering process work?

If you're not totally new to the music production process you probably have a good idea on the mastering process. It's not that different from the mixing process, actually, although it has a distinct purpose. When you are mastering your song or an album, you should be in the final step of audio post-production. Keep in mind, that your purpose while doing the mastering is to balance the music, the elements of a stereo mix, and optimize playback across all systems and media formats. But how do you achieve an optimal mastering? What is involved? Mastering process consists (mainly and basically) of those processes:

• equalization;
• compression;
• limiting;
• stereo enhancement.

These will sum it up for you. However, note that the entire process could have more processes involved. But most of them could be included in the four main topics listed above, which we'll see in details below.

Equalization

This is probably the skill you'll be required to understand most of it. That's because you need to understand about equalization to adjust each of your tracks separately, during mixing stages. Adding equalization could mean the difference from a good song to a great song. At first, make sure you use gentle, broad stroke adjustments to help subtly change the perception of dynamics and loudness of the track. Your goal is to make the sound better without it sounding like it’s been equalized. Once you have finished with the subtle broad stroke adjustments, move on to isolating any problem frequency by scanning the entire audio spectrum with a narrow bandwidth and attenuate any problem frequencies. If you have done this before, you probably know that sometimes fixing something is beyond the scope of the mastering process. Eventually, you'll learn that trying too hard to solve equalization issues can cause as many problems as you solve. Ideally, mastering seeks for a "flat" sound. For instance, even though you are looking for strong bass, you should never equalize pushing up that bass. You should always use the equalizer once, not while finishing off the audio, but instead, during the reproduction of the already finished file.

Compression

Just like equalization, compression is as much important and you should care about it. Objectively, the compression process is a great way for you to add punch to your mix as well as a sense of overall control. If you use it properly, it can make your recordings sound richer and more energetic, plus it can help ensure that the various sections of your song flow well into one another. If you are researching the topic, I would like to point you out to a few topics of interest. Things I recommend you to know when you start compressing a master audio file:

Know how it works

Threshold, Ratio, Attack, Release, Soft vs. Hard Knee, Make-Up Gain... Are you taking notes? You should. All those terms are important to know for you to understand how the compression process works.

Less is more

Do not over-compress. Most platforms now use LUFS as a way for measuring and (in some cases) adjusting music files. Eventually, as you learn more mixing and mastering technics, you'll see that in some situations compression is optional. Additionally, you will understand that not every compressor is a mastering compressor. Take a multiband compressor for instance, it can be a wonderful allied when used correctly in the master channel.

Stereo Enhancement

A Stereo enhancer is a plug-in you use to expand the stereo width of stereo audio material. It cannot be used with mono files. Basically, a stereo enhancer consists of four main controls, width, delay, color, and mono. The best way for me to explain how stereo enhancement works is through this video. But in short, a stereo enhancer/ widener plug-in should give the song a strong stereo image. You can take the following as an example. When you listen to a piece of amazing music that paints a crystal clear picture of which instruments are playing and where they are in relation to you, that’s a song that has a good stereo image. Now, you can achieve that in numerous ways, but we're not digging deeper into the subject. Otherwise, the article would lose focus and would get unnecessarily longer.

Limiting

If you got to this point you should be aware that limiting is the final step in the mastering process. Which, by the way, is considered by many the most important. By limiting, your objective should be to make your track as loud as possible without clipping or distortion. That's simple enough, right? That's actually way easier said than done. Before working with any limiting plug-in, you should first learn its basics. For instance, did you know that limiters are essentially compressors with extremely high compression ratios? Also, differently from compressors, limiters should always be the last plug-in you use. Actually, in some cases when you added a fair amount of compression to the stereo bus while mixing, you can add a limiter just to keep your peaks in check. Just by looking at the waveform, you should able to tell whether there are lots of peaks in the track; if not, you probably don’t need to add any compression. Eventually, you'll learn that when it comes to limiting, just like many other mastering processes, less is more.

Why should you care about mastering?

In short, when you master your album, you're making sure that the song one doesn't blow out the speakers while the next song is barely audible. The mixing process extends to this, but mastering takes a broader view. I got asked once if the mastering process was really necessary. There is only one answer to that question and it's a big YES. Below I'm going to list you a few compelling reasons: Uniformity in volume and level - The mastering process raises or lowers the overall level of the tracks and makes each track on the album uniform. This allows, for instance, for listening to at entire album through a stereo at one volume level instead of having to adjust the level for each song. Additionally, it also allows the music to be played from a variety of sound systems, whether it's a car stereo or earbuds. Consistent sound - Especially in albums, mastering will make tracks sound like they were recorded and mixed at the same time and place. Improve the quality of your music - As previously mentioned, that is the main purpose when you master a song or an album. In this very competitive music scene, your chances to make it in the music business dramatically decrease if you don't have your music properly mastered. Adequate loudness levels - It's not just about making your music sound loud (loudness war is over), it's about adequating your music to different platforms.

Things you should know about Mastering

As a countermeasure for the loudness war we've mentioned above, most mastering software today have features that help to keep the loudness level at similar points. That makes the more compressed mixes (which should be louder) to be lowered. That way, it makes no difference if you're trying to master your music into very high audio levels, louder than the others. If you're reading this article, chances are that you probably have already tried to master a song. Maybe you already have some good mastering skills. However, did you knew that there are two different mastering styles?

Traditional

Consists of mixing with the master peak level hitting quite far away from the 0dbFS (limit). I'm pretty sure everyone has his own way to do it. If you send your master to someone else, if you happen to work with more than one mastering engineer, you already know that. As an example, some mastering engineers will ask you to send your final mix with peaks not over -6dBFS. Those are the most popular ones, the "modern mastering engineers", the ones that got used to people asking them "I want my music to sound loud". However, there are some mastering engineers that will require -8, others even -10, -12, -14 or -18dBFS. If that's your case, you have to understand that those are the mastering engineers that see the mastering process as a whole separate process (from the mixing process). The more room you give them, the better they can have the work done. Unfortunately, it doesn't just comes down to you giving them plenty of space to work with. It's also necessary that the instruments must be finalized with a high "crest factor" (relation between average and peak). In simple words, without ultra compressors, and no limiters. Tip: Just go with moderate compression and you should be fine here.

Alternative

Personally, back when I was working with Electronic Dance Music, that is how I did things. You mix while you're mastering, altogether. That because, eventually, you get used with your references and you know what are you seeking when it comes to the final recording. For that purpose, you can add a limiter directly into your mix and compressor in the master channel to finalize near the mark 0. It's not a question of which one is best, is more like to which one you adapt better. "Alternative" mastering is good if you have a standard, almost the same instruments, same levels, just with a few differences here and there. Now, if you're always exploring new and different musical styles, instruments, vocals, and so on, you better stick to the "traditional" mastering.

Hiring someone to do the Mastering? Here is what you need to know

The mastering process takes a lot from you, trust me. Sometimes you're just not very familiar with the process, so it's completely ok to send the final mixes to someone else to master them. If that's the case, here we have a few tips to help you (and the mastering engineer) to run things smoothly during the deal. First off, if you send him a -6 dBFS mix you are not helping! Honestly, you're even making things harder for him. If you want your master to sound loud, you got to ask him to do that, let him "crunk it up" for you, just give him plenty of space. Also, make sure you adjust the snare and the kick drum (but especially the snare) a little higher than it should be. Something around 3, even 6 dB depending on the final compression level you want. The snare disappears by smashing the mix during the master!

Finalizing audio levels for Mastering

In an attempt to "rescue" the artistic part of the music that was being lost due to the so-called ultra-compression, important names came up in favor of a lighter use of compressors during the finalization of the audios. Among them Bobcats, who created the “K” pattern (K-8 / K-10 / K-14). The 'K', followed by a numerical representation, represents RMS average completion levels. In a simplified way, Bobcats scale pretends that 0dBFS is the value of his scale. For example, K-8 pretends that -8dBFS is 0dB. And of course, you must work with all 0dB constraints by pretending to be at -8dBFS. That helps you to keep the mix more dynamic.

RMS levels throughout the years

I took this information from a very interesting Reddit discussion I've found. I'll sum it up for you. In short, they list some very well known producer names in the Electronic Dance Music scene and the RMS levels of their music. So we have, Fedde Le Grand's "Where We Belong" song with -6.04, Martin Garrix's "Wizard" with 4.98, Knife Party's "Internet Friends" (-5.04), and the list goes on. Do you see my point? -4 dB RMS is really loud. I can say that in the last 1, maybe 2 years, we have moved from -8dB RMS to about -5 as an average. But that's not something unique just to the EDM. The picture below shows us some detailed information on the RMS progression during the years (credits in the pic and also to Wikipedia and whoever edited/ created the post). Three different releases of ZZ Top's song "Sharp Dressed Man" show increasing loudness over time (1983–2000–2008).

In conclusion

Let me just get started by telling you this: You shouldn't have to worry about loudness in the first place, if your music is good, people can just turn it up. If you're sending your final mix to someone else master it, follow the steps above and you'll be fine. However, if you're planning to do it yourself, that's also ok. Just remember a few last things I'm going to tell and you'll be fine:

• Consider where you want to get with your master. Planning to release your music to a specific service? Know their limits and don't master your song above that;
• Do you have a song you like and which is similar to yours and to what you want to achieve? Compare it to yours while mastering;
• Studying (a lot) about the genre you're producing and mastering technics should also help. Use meters and keep things simple at first, with just 3 tools (EQ, compression, and peak limiting).

I'm afraid that there is a lot more I could tell you here. But as a musician, you know that all comes down to two things: hard work and patience. And of course, you can always find top-notch articles here to help you get where you want, just keep it up.