(previous note: Along the guide I will mention the names of real analogue gear and next the Nebula libraries that emulate these in parentheses. The “mojo” and not functional hardware emulations libraries have asterisk signal (*))
Mastering, a form of audio post-production, is the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device (the master); the source from which all copies will be produced (via methods such as pressing, duplication or replication).
All this implies a specific audio treatment where a number of tasks such as fixing defects, normalize volume, giving a final finish to the sound that stimulates the listener, etc ...
To perform this procedure is used different hardware / software audio elements, such as equalizers, compressors, enhancers, limiters ...
These components are set in a specific order by passing the audio signal so capable of influencing the sound properly as a whole.
This mean that when analog devices are used these are physically connected to each other forming the chain of hardware units that act simultaneously on the sound, and this will determinate that the mastering engineer when they not make explicit use of any of components of the chain (no EQ or compress with some equalizer / compressor specific, for example) does let pass the audio signal on them in "bypass" mode in order to add the behavior / harmonics hardware although it is not acting on this sound and get the overall result of the joint action of the chain at all times.
The development of differents mastering chains is not arbitrary and are based on a number of technical requirements that determine the possible options in the use of various elements of existing hardware and order established between them so that they get optimal and specific results.
The things mentioned earlier has also transferred to our personal work with emulations of analog equipment of Nebula and we must establish on our part the various mastering chains we use in the correct way basing on valid technical an artistic reasons and develop them opening different instances of Nebula with specific presets of equalizers, compressors, etc ... with a predetermined beforehand order in channels inserts of DAW / audio software. We can also use Nebula with any other software if we wish it, as "pre" for other equalizers, compressors, ... plugs or using them in combination.
Also say that mastering with Nebula is made in a single step and can not be done in different phases. I mean by this that all Nebula emulations and conventional plugs that we use for do the mastering have to be present simultaneously at the same time in the DAW/ other software project when we export the final mastering.
I will propose an example of hardware chain widely used in mastering studios that will be very useful for you. In turn I will make mention of the Nebula libraries that would be required to implement this example chain that I explain following.
It´s also common to see in mastering use of tube enhancers and aural exciters for audio processing in order to add bright - warmth, restore harmonic content, ... I will do a special mention of all these too.
Based on the above, the mastering chain that I´d want suggest would be:
This is a continuum of hardware elements where you use only the components that you need for make your mastering.
Now I´ll explain the Nebula libraries necessary to develop the chain that I have mentioned. In some cases you will have to choose one of various options in the same section (I´ll specify it in parentheses with the words “choose one”)
EQUALIZERS AND COMPRESSORS FOR MASTERING
In this part o the chain we set the analog equipments for carry out tasks of EQ / compression in the original mix for get optimal finish.
The equipments/ tasks required for this process would be:
-A parametric equalizer for clean/ correct frequencies
-A VCA compressor for retain peaks and obtain unity
-A shelving EQ to add color and give character
-A Pultec style equalizer for get more air and brightness
-A Variable MU compressor to add color and shape the sound
Hence, and based on the above, the instances of Nebula, the emulations that would be needed and the specific order that it should have be established like follows:
-Pultec style equalizer
-Variable MU compressor
Here you have the libraries would be more appropriate to develop this. As I have mentioned before you only have to choose one of them in each section.
These hardware devices will allow us to act on the different harmonics in order to increase the "apparent" level of a frequencies range without raise the "real" signal level (not dB is added to the signal ). This will enable us to treat the sound in a certain way to achieve a number of specific objectives such as add warmth and brightness, increase the apparent perception of loudness, etc ...
In this section we´re going to indicate a pair of tape recorder emulations from Cdsoundmaster libraries more related to mastering tasks, and a pair of tape recorder emulations from Signaltonize more focused to mastering too.
We aren´t going to use tape saturation in this part of the audio production because in mastering is most convenient use the tape recorder in clean mode.
Include in “The Apex Tape Collection” library from Cdsoundmaster
Nebula can´t emulate brickwall limiters due to technical limitations, this is the reason because we have to use plugs of other type of software. Limiters highly recomended are:
There are two mastering console emulations for Nebula very interesting too. These libraries include the equalizer for use in mastering tasks and its own input/ output presets that you have to conveniently place along mastering chain.
I use 2 limiter instances (of same brand limiter = no Nebula) one for limit pre-fader (aesthetic, DR usage) and other for brick-wall limiting (x4 OVS) for put levels in the rule (r-128, K-meter V2, etc) in post-fader.
Enrique Silveti. Acustica Audio customer and technical support.