We attended this master class by Michel Martín on microphone techniques for vocal recording, covering topics such as correcting tonal problems through mic choice, the right combination of mics and preamps, recording and production tricks, series and parallel processing, and more. ISP is pleased to give its readers the ins and outs of this new master class which, as with the previous one, turned out to be extremely interesting.
The perfect take
As was rightly pointed out at the very beginning of the class, people often believe that vocal recording is simple, because the technical complexity doesn't seem very high. Mic, pop filter, preamp, maybe a bit of EQ and gentle compression... and you're ready to record.
However, every voice is different, they all offer a great number of nuances and details, and few have a balanced timbre. That's why the apparent simplicity of the signal chain turns out to be more of a limitation than a benefit: with "few" resources, you have to tackle recording the instrument the human ear is most accustomed to.
The word "few" is in quotation marks because, as we saw throughout the day, there are actually hundreds of small details and techniques that help achieve the elusive "perfect take."
Course materials
The handout began by covering theoretical aspects to keep in mind, such as the physiology of the vocal tract, the different human vocal ranges, and the tonal and temporal characteristics of the voice.
It then went deeper into other issues, such as speech intelligibility and the various parameters that affect it, the types of phonemes that exist (stationary/non-stationary, vowels, voiced consonants, fricatives, etc.), and how vowel formants each have two distinct frequency ranges.
It also explained the most common choir arrangements, as well as stereo mic techniques for capturing this type of ensemble, and how some mics have different capsules to counteract the high-frequency absorption caused by the relative humidity of the air.
Moving on to other ground, the materials reviewed the most common types of mic (moving-coil/ribbon dynamics and condensers), and how the physical construction of the transducer itself makes each mic respond differently, and therefore makes it better suited to one type of voice or another (or to one production or another).
Following on from these ideas, Michel talked about microphone EQ and how it's preferable to play with mic types (both their transducer and their polar pattern) and position to get the desired timbre straight from the source, without needing to EQ.
For example, to capture a somewhat "thin" voice, you can use a tube mic that colors the low end and adds body, or you can play with the proximity effect of pressure-gradient mics to achieve a similar result. Conversely, a very "dull" voice can be recorded with a mic that boosts the treble, adding some sparkle in the high frequencies.
Another interesting topic covered was choosing the right mic-preamp pairing. The most common mic preamps were analyzed, and a summary chart was provided classifying them by their characteristics in terms of bright/dark and transparent/with character.
Regarding dynamic processing of the voice, the topics included using sidechain compression to tackle sibilance (de-essing), series compression to solve problems with wide dynamics (better to use two compressors with little gain reduction than a single one with a lot), and parallel compression as a way to enjoy the sound of heavy compression on the voice without losing all of its dynamics.
Emphasis was also placed on the fact that the shortest signal chain is often preferable (in the sense of having as little processing as possible), but that you also have to lose your fear of processing while recording (as long as you know what you're doing!).
Finally, he showed how mic orientation can help achieve a certain timbre or reduce some problems (plosive consonants, for example), something that could be tested in practice in the second part of the master class.
The materials concluded with a selection of the mics most commonly found in recording studios, classified according to scenarios involving deep voices, thin voices, voices with sibilance problems, weak voices, and so on.
As in the drum master class, the materials were interesting in their own right, and the instructor supplemented them with many comments and tricks, and by answering attendees' questions.
Getting down to work
After a well-deserved lunch break, the practical part of the class began in CATA's Studio 2. There we were met by Santiago Quizhpe (the studio assistant), who set up the two mics used for the tests: a Neumann U67 and a Violet Design Dolly.
The first, a tube mic, was run through a solid-state preamp from Kahayan, and the second was wired to one of the available Avalon 737s. Both used the same Apogee AD conversion, and the DAW was Pro Tools|HD 8, controlled from a Yamaha DM 2000.
For the tests, two students from ABC Estudio, the singing school run by Ángela Carrasco, took part. Moisés Franco provided the male voice and Geniri Mena the female voice, both standout students at the school.
In this part of the master class, we could hear how each preamp-mic combination responded differently depending on the singer's type of voice, dynamics, distance from the mic, and so on.
There was also discussion of how to treat the voice according to its dynamics and how, in quiet passages, a boost in the lows and highs can help define the voice and give it body, while in loud passages a slight cut in the mids can help it blend better in the mix.
The tilt and orientation of the mic relative to the singer's mouth and chest were also discussed, as well as how details such as putting the pop filter on a separate stand help prevent noise from being transmitted to the microphone.
As an example of using processors while recording, each mic input was duplicated (the Neumann and the Dolly were recorded simultaneously), and a limiter was inserted on each to show how a couple of dB of reduction can work wonders on the voice... partly because if the singer hears that their voice sounds great, they'll probably sing with more confidence and better.
And this leads to one of the most interesting things discussed in the class: the psychological side of recording. Knowing how to handle the artist in the studio is always important, but when it comes to vocal recording, this becomes even more important.
Michel explained that technology should be at the service of the artist, so that they feel comfortable and can give their best. The goal is to capture memorable, magical moments in which the listener doesn't notice how the voice was recorded, but rather the soul it has and what it conveys.
Venturing a little into the (vast) territory of music production, examples were chosen from legendary producers, such as Quincy Jones, to explain how they approach vocal production. Many of these iconic producers not only take into account the psychological and technical aspects of recording, they are also aware at all times of the vocal melody, and build all the instrumentation and arrangements around it.
Conclusions
So ends our report on a day packed with useful, practical, "ready-to-use" information. Due to obvious space limitations, we can't go into every issue addressed in the master class, but we have tried to show how it covered a great number of essential aspects.
From theoretical questions that lay the groundwork for better understanding the logic behind certain practices, through numerous "tricks" and techniques that help solve common problems, to aspects of recording that, while less tangible, certainly have to be considered in order to achieve the perfect take.
About the instructor
A graduate of the Polytechnic University of Valencia in Audio and Sound Reinforcement Systems (who has also studied Electronics, Electroacoustics and Psychoacoustics), Michel Martín has spent more than 25 years in the world of music and has worked with artists of the caliber of B.B. King, Take That, Amaral, La Oreja de Van Gogh, Estopa, Alaska y Dinarama, Los Ronaldos, Los Bravos, Mecano and Marta Sánchez... to name just a few.
Fortunately, all this experience doesn't stay with him alone, and Michel has been teaching in Spain for many years at several different schools. More than one ISP reader has probably had the chance to attend one of his classes.
