Whether it’s the Italian opera or East Coast battle rap, the sweetest pop ballad or the most sinister growl, the human voice has had a special place in music for as long as music is around. The vocals not only convey the textual message, but also a large part of the emotional content of a song. After all, we learn from an early age to evaluate the finest emotional vibrations and modulations in the human voice.
Some (I’m one of them) even claim that in popular music you can often get away with average overall production quality if only the vocals are produced professionally, and the rhythm section creates the proper groove.
However, vocal production doesn’t simply mean “recording”! The creative use of voice-altering effects has not only been an integral part of pop music production since Cher’s Autotune-hit “Believe”. Often not even noticed by laymen, the trained ear recognizes in productions across all musical genres the creative intervention of the sound engineer, who – sometimes more, sometimes less subtly – helps shape the sound image.
It’s no surprise, therefore, that vocal production has a high significance in modern music production, and that it’s not uncommon to spend a small fortune on the right equipment to capture exactly the kind of result that perfectly flatters the voice in question and perfectly matches the desired musical effect.
What belongs to a vocal chain?
As great as the influence of acoustics, vocal technique, microphone placement, editing and mixing may be, when people talk about a vocal chain, they are usually referring to the technical components of the recording chain. In the simplest case, this is a microphone, a cable, and an audio interface, but can also include multiple microphones, amplifiers, compressors, reverbs, tape recorders, equalizers, carefully selected converters and clock generators; and not to mention effects such as Auto-Tune, vocoders, pitch shifters, harmonizers, chorus, and so on. In short: it can get quite complex (and also expensive)!
Let’s start with the basics: To turn acoustic sound waves first into alternating electrical voltage and then into digital data that can be recorded (we’ll ignore purely analog recordings here), a total of two conversions are necessary. The first is done by the microphone, the second by a digital converter. To ensure that these two get along well in terms of level and impedance, a microphone amplifier is the linking element.
Even the simplest desktop interface consists of a preamplifier and converter, which are combined in one housing for the sake of simplicity. In some cases, these two components are even placed inside the microphone housing (so-called “digital microphones”). However, many professional sound engineers appreciate the possibility of being able to freely combine different devices in order to have maximum control over the sound design.
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How big is the sound impact of which device?
In practice, one rarely has the opportunity to compare hundreds of microphones, amplifiers, compressors, converters, etc. and to explore the often complex interactions. And your test vocalist will probably (rightly) leave the studio in a rage after the tenth preamp switch. So it makes sense to be able to realistically assess the influence of the various elements in the recording chain, so that you know where to start and what to expect. There is no substitute for practical ear training, but I would like to give you a rough guide that you can build on with your own experience.
The choice of the right microphone has the greatest influence in a vocal chain (at least on the technical side). Logically, after all, all subsequent devices can only build on the signal that the microphone provides. Microphones come in a wide variety of designs and with many different polar patterns, frequency responses and dynamic ranges. The microphone should always be chosen so that it comes as close as possible to the desired end result, as it is often almost impossible to turn an unfavorable microphone choice into a professional product in post-production. It is worth investing time and money in choosing a vocal microphone and, if possible, having a small selection in your collection to enable a direct comparison at the source.
By the way, the most expensive microphone is not always the best. The optimal choice depends on various factors and can vary greatly for a different vocalist or song (or even song part).
Preamplifiers, also spelled preamps, are an important component of the signal chain often underestimated by beginners. Many of them have a very characteristic sound of their own, which is often determined by input and output transformers, characteristic amplifier components and of course the circuit design itself. At least one decent preamplifier is mandatory, but investing in a selection of them is usually not worthwhile until a small pool of different microphones has already been accumulated. For starters, the built-in microphone preamp of a mid- to high-end audio interface will do.
It is important to understand that preamps interact with the connected microphone. I’ll spare you the electrotechnical details here, but you should know that a microphone can sometimes develop a completely new character or detail on a different amplifier, primarily due to the amplifier’s input impedance. Many vintage preamps, for example, have a much lower impedance than modern amplifiers, which has a certain effect on the behavior of the connected microphone. Some preamps therefore even offer a switchable input impedance to be able to recall two sounds in one device.
By the way: pay attention to how your preamp sounds in different gain ranges. Often, especially cheaper preamps have a much poorer resolution in the lowest and upper quarters of the gain range, and it can make sense to raise the level digitally in the DAW to take advantage of the preamp’s “sweet spot”.
When it comes to sound processing, workflows can differ greatly. Some prefer to record a completely unprocessed signal, others strive for the final result right at the source. This also depends on the respective situation; there is no such thing as the right way to do it.
However, for the small budget and/or engineers with little professional experience, it generally makes sense to limit yourself to the basic chain of microphone, preamp and converter first. Concentrate on the session and the performance first! This will save you long setting times and annoying re-plugging and protect you from messed up recordings in case a compressor (or whatever) was set unfavorably after all. Once you have gained enough experience, you will be able to judge for yourself which devices make sense for your way of working and your sonic preferences. Normally, this will be a carefully selected EQ/compressor combination that optimally fits the requirements you are most often confronted with and therefore helps both your sound and workflow.
I would generally leave de-essing out of the recording chain, and if reverberation or echoes are recorded, they should of course be recorded on an extra track, so they can simply be replaced or altered in the mix at any time.
By the way: pay attention to the order of your sound processing! For example, a compressor will produce different results if you EQ the signal beforehand.
Yes, converters do influence the sound. However, even inexpensive modern digital converters usually operate at such a high level that the sound influence is usually negligible compared to the other factors.
As long as you’re not dealing with malfunction or defect, and the converter is from this century, it’s unlikely that a fantastic recording will be ruined by the influence of the converter (which can absolutely happen with a microphone, compressor, etc.). However, if you’ve already refined all other aspects of your vocal chain down to the last detail and are still in the mood for technology, you can venture into the world of converters and clock generators to bring out the final details there. Here, however, the “law of diminishing returns” quickly takes effect: for 1% improvement, the price can increase tenfold.
For the sake of completeness, I would like to mention that there are digital converters with transformers or even tape emulations etc. that deliberately influence the sound – this is of course something different and you can certainly use these devices to shape the sound, but of course it is not the conversion itself that is responsible for the sound.
By the way: since converters and interfaces are often combined in one device in practice, it makes sense to select digital interfaces primarily with workflow and compatibility in mind. So don’t worry too much about converter sound and quality at first, but rather ask yourself how many channels and which connections you need, whether you can use integrated DSP effects or whether the setup should be mobile.
What about FX?
Creative effects are extremely diverse and are sometimes used so dominantly that they can actually drown out the sound influence of all the above-mentioned components. For example, if the vocal is run through a vocoder, the influence of the mic preamp is negligible, and the subtle overtone colorations of the hardware compressor may hardly matter when the vocals are then sent through a Marshall at high gain. Nevertheless: Every coloring device in audio engineering has a certain dependence on the input signal and the sequence is highly relevant, so here the influence can hardly be generalized.
Of course, the scope of a blog post only allows for a rough overview of such a subject. Nevertheless, I hope that the article could give you a good overview and help you in the selection and composition of your own perfect vocal chain, so that you can concentrate on the essentials: your music!
What does the vocal chain of your dreams look like? Are you constantly searching for sonic perfection, or should it be cheap and easy to use? Feel free to share your ideas and favorite devices with us in the comments!