So what is called "mastering"? It is a special procedure, which must be applied to a musical track after it was finished. It makes your music sound deservingly in a comparison to other high quality recordings. There are several types of mastering, each of them intended for a certain type of media.
For example, if your track is intended to be broadcasted on a radio station, then a special radio mastering must be applied to it with a special parameters suitable for radio broadcasting. First of all, radio mastering features more compression ratio and more dense sound. There is also a vinyl mastering. It is a special type of mastering, and it is being made directly by those sound engineers, who does vinyl publishing at the factory. This type of mastering features more compression ratio, less balance of low frequencies, and less wide stereo-image, especially at low frequencies. It is made to provide a correct recording parameters on vinyl, such as enough distance between tracks to avoid the needle to jump between neighbouring tracks during playback.
But we have distracted a little bit away from our topic. We will talk here about usual type of audio-mastering, which is more suitable to be played on a home audio system, or in the night club.
Let's consider the main tasks of mastering:
- Balancing the frequency spectrum. In a correct sounding track all the frequencies must sound in a good balance. It means, that it must not allow any non-comfortable for hearing predominance of low frequencies (bass) over the others, or vice verse, a lack of low frequencies and predominance of highs, and also a dis-balance in middle range frequencies. This is done by using Equalizer, and also by compressing a separate frequency bands of the sound spectrum.
- Signal compression. It is done to reduce a difference in volume between silent and loud parts of your mix, for more solid and dense sound. It also prevents volume to be overlouded in some loud places of the mix, and it holds your sound in a certain volume corridor, not lower and not higher.
- Stereo image enhancement. You probably have noticed, that firm recordings sound wide enough over the stereo base. It is made by special plug-ins - stereo image enhancers.
- Adding a non-linear distortion to a certain frequency bands. It is done by plug-ins, called Saturators and Exciters. The thing is that our ears accepts a slightly distorted signal more naturally, than a clean digital signal without any distortions, and this is the nature of our ears. Slightly distorted sound seems to us more warm and analogue. But don't overdo with this procedure, because over-saturation can cause non-comfortable distortion and clipping effect. In any case, each operation is done in accordance to ear. You should from time to time compare your mix to some reference high-quality firm track, and try to achieve that result and correct your errors.
- Peak Limiting and volume maximizing of your track, with absence of audible sound distortions. The thing is that limiting operation is the only way to rise up the output volume or RMS of your track, but it is also drastically affects and changes your final sound. For example, if you overdo with limiting, you will hear audible sound distortions and blurring the drums and other rhythmical details in your mix.
There are many mastering methods and algorithms. Each of them has its own advantages and disadvantages. You can spend years in searching information thru Internet on this topic and trying to find the best algorithm and plug-ins set for your demands. But I am here to help you and to make this problem many many times simpler.
So, here's my secret technique. I will tell you about my own mastering method, which I developed during last ten years making thousands of different experiments with different plug-ins and their parameters. However, to tell the truth, it is not a panacea. Don't think that you can just copy all my settings and your mixes will instantly sound super, not. But,this knowledge will significantly ease a mastering process for you, and after some time you will learn to setup your master plug-ins simply enough (with some experience) and will achieve more or less quality sound.
I use following VST plug-ins in my master bus, in the following order (according to the signal flow):
- Sidechain compressor Waves C1 comp-sc
- Izotope Ozone 4
- PSP MixSaturator 2
- Waves L2 Ultramaximizer
And now let's make a closer look to this mastering chain.
First in my master chain is equalizer. It can be any of plug-ins you prefer, but I use built-in ableton's EQ-Eight. In its settings I put a mark near "Hi Quality". I usually cut a super-low frequencies with this Eq, that are lower than 32 Hz. It is made to avoid unnecessary low-frequency noise and DC-offset, and also it boosts low frequencies, that are slightly above 32 Hz, because they go into a resonance with a cutting filter contour of the Eq. More to say, I make this low cutting not in every track, because sometimes it makes by kick drum sound worse, but sometimes vice versa, makes it sound better. One more important role of this Eq is that I use it's output volume control to artificially rise of lower the volume of some places in my track, creating additional dynamics, which is sometimes lacks in the track.
2. Side-chain compressor
Second in my master chain is sidechain compressor, and I use VST plug-in "Waves C1 comp-sc" for it. It helps to make a kick drum sound more "punchy" along the track, so called "pumping effect". Again, I use this plug-in in my master chain not in every my project, because sometimes it can lead to Ð° worst sounding, depending on a character of a kick drum sample. It may cause audible oscillations and non-comfortable overfalls of sound volume.
3. VST Plug-in Izotope Ozone 4
This in an excellent VST-plug-in, and I cannot even imagine any digital mastering process without it. It consists from several mastering modules, and represents a full tool set for a mastering. But I don't like the work of some certain modules inside it, that's why I use Ozone not alone, but together with other plug-ins, which remove this disadvantages. Inside Ozone 4 in accordance with my method the signal flows through next internal modules:
- Equalizer, in which I fix frequency balance, and add some frequencies that are lack in the mix, and remove some non-suitable frequencies. This EQ has mostly a cosmetic character; you can add and remove frequencies maximum at plus/minus 2 dB, in some cases at 3 dB. We are giving here some slightly colouring to the sound, not more. One more moment about this EQ. I often cut a super-high frequencies over 18 kHz in it. This slightly dampers and muffles the general sound, and thus, making it more "warm" and analog-like.
- Multiband dynamics. After EQ inside Ozone the sound comes to a Multiband dynamics module. From this moment, the whole sound splits on 4 frequency bands - lows (super bass, kick drum), middle (bass, vocal, melodic instruments, drums), high (cymbals, hi-hats, snare drum, clapper, and a high clicking sound of the kick drum's plastic), and super-high band, which is responsible for a crystallines and cleanness of the mix. Then, the processing is made on each of four frequency bands individually. Module Multiband dynamics represents three processors in one block, it's a compressor, a limiter and an expander. Each processing has its own settings, and I will tell about them later in more detail. Compressor is needed to soften a difference between loud and flat places in the mix; Limiter - limits peaks, think of it as a compressor with more fast time of action and more level of reacting; and Expander, intended for rising or killing the most silent parts (e.g. noise) in the mix, I usually never use it in mastering process.
- Multiband Harmonic Exciter. After compression the sound flows here to this module. Multiband Harmonic Exciter adds non-linear distortions to each of the four bands individually. Usually, I add it a little bit to the low band, increasing a bass line reading and adding it a more depth. To high band, it adds analog "warmth" to the sound. And to super-high band, where it rises a crystallines and cleanness of the mix.
- Multiband Stereo Imaging. This module is intended for widening stereo base of each frequency band. Usually, I slightly expand a stereo base of three upper bands, and on the low band vice versa, slightly narrow it.
- Loudness Maximizer. After stereo enhancer module all four bands are mixing together again into one wide-band sound, which flows then to a Loudness Maximizer module. It is a mastering limiter, which cuts loud peak levels and rises up a volume (RMS) of the whole mix. It is the last output module inside Izotope Ozone 4. Next, sound flows on to two more plug-ins, described below.
4. PSP MixSaturator 2
This plug-in is intended for adding some warmth to the sound. I use it manly for boosting bass frequencies of the mix. I will tell in detail about this plug-in in one of my next articles.
5. Waves L2-Ultramaximizer
This is a last plug-in in a master chain of my algorithm. It's a limiter, but I mainly don't use it by it's main intention, I set it's Threshold value to zero. In such configuration this plug-in cuts only those peaks, that jump over 0 dB (the most loud sound level in a digital sound), and avoids the clipping of the signal. In details it will be described later in one of my next publications.
I assign all theese plug-ins to the master-section of my ableton's project., inside evety my musical composition. I must notice that professionals recommend to do mastering inside another separate program, after you exported the whole your mix to a wav file. But I didn't find this to be comfortable, I prefer to do anything inside one program. Because for example if at the mastering process you will notice, that the kick drum or some other sound became to sound not in balance, too quiet or too loud, then you can slightly correct its volume right here in your project by changing volume or Eq setting, and there will be no need to export the whole file again (time consuming) to another separate mastering program.
More two words about when you should to switch on the mastering plug-ins. Do not switch master chain while creating your track, because it will lead you to an incorrect instrument and sound balancing. The order is as follows: at first you write your complete track, balancing all the instruments by volume and frequencies between each other. While doing that, you can only leave the last plug-in - Waves L2 - in ON state. Other master pluig-ins must be OFF. After that, when the whole track is finished, and you think it sounds good enough and balanced, then do begin a mastering process. Switch all master plug-ins on and setup their settings. And another thing, if you will want to add a new instrument or new sound to your mix, or to change one sound with another, then in this case you should switch off your master plug-ins, add that new thing to your track, balance it with volume and frequencies, and then switch on your master plug-ins again. And, probably, you'll have to go through the procedure of tuning settings of all your master plug-ins again from the beginning, because your track has been changed, and it's frequency and dynamical characteristics have been changed too, and it mean that all the master plug-ins should be reconfigured.
In my next articles we will talk in detail about how to set up each master plug-in.
Written by Jim Pavloff, 2010