Recording Vocals (Part I)
This is the first part of a feature about vocal recording, with some ideas, tricks and simple but useful techniques you may use when recording one of the most amazing and complex instruments of all.
This first episode will verse about technical aspects, and the second part will dive into more delicate matters…
Recording vocals may seem an easy thing, but it is probably one of the most difficult elements to obtain a great sound from.
It´s an instrument with a very wide register (both frequency and harmonic-wise, but also regarding dynamics), and moreover, it is a sound our ears are very familiarized with.
The voice presents a lot of nuances, so it is logical that when recording it, there may be a lot of little details that can make a big difference: microphone type, placement, polar pattern, preamp, processing…
And this is only speaking about technical matters. The real difficulty, the truly delicate thing, is more to do with the field of human relations.
Even if your recording chain is superb and has been perfectly tailored to the singer, if he/she is not ‘inside’ the song, maybe the recording will be technically correct, but probably the performance will not touch the listener.
A record becomes big only when the songs stop being the artist´s and the listener makes them their own. This can only happen when something touches the person listening.
As I see it, a great recording is one that captures a magical moment, one in which the listener won´t pay attention to how well the vocal was recorded, but to the emotions it conveys, to its soul.
A correct performance, even in front of a millionaire signal chain, won´t transcend that ‘correctness’. However, an exceptional performance may transmit hundreds of emotions to the listener, and then it almost doesn´t matter what mic was used to record it.
That ‘almost’ is there for two reasons. On the one hand, there´s of course some basic quality that must be achieved; on the other, that very same performance could be transformed into something even more powerful, if attention is paid to the appropriate technical aspects.
So, in this feature both ‘technical’ and ‘human’ sides will be addressed.
The first part will cover various technical aspects that may be taken into account when recording vocals, and the second installment will get into a deeper subject: how to use these (and other tools), in order to obtain the very best from the performer.
What mic should I use?
The best answer to this question is: ‘try some’.
When recording vocals, it is very common to compare some of the mics available in the studio, to check how each of them responds to that particular singer´s voice.
It is something easy to do: the microphones are placed side by side, and the singer performs a fragment of the song through each of them. Preferably, this fragment should contain both the softest and strongest parts – in dynamics – of the song.
When listening to the separate signals, usually a certain mic seems more appropriate than others.
It may be because it makes the voice sound more natural, provides a certain ‘air’, manages the dynamic changes better, smooths over some undesired aspect of the voice, the singer ‘recognizes’ his voice better with it…
As Csaba Petocz (Metallica, Stevie Nicks, Aretha Franklin) puts it, “The perfect vocal microphone does not exist, there are simply different mics for different people”.Take a look at the article Vocal Mic Shootout for more details on this process, there are also audio files recorded with five exceptional mics: AKG C12, Neumann U47, Neumann U67, Manley Gold, and Blue Bottle. (The article is not yet translated into English)
Looking at those five mics, you´ll notice all of them are large diaphragm condenser mics (3/4’’ or more). These kinds of mics are usually selected for vocal recordings.
This is not because an LDC captures more bass frequencies than an SDC (a common misconception). In fact, a smaller diaphragm ‘can be moved’ more easily, so the response of these mics is usually more precise along a wider part of the frequency spectrum.
However, what is true is that the coloration introduced by an LDC may make the voice sound warmer, with more body. Besides, the sensibility of these types of mics is usually higher (than an SDC) due to their bigger diaphragm.
Regarding other transducer types, usually ribbon microphones don´t extend to frequencies as high as condenser mics do, and this may impart certain character to the voice.
These types of mics were the usual choice when recording vocals before the first condenser microphones appeared (around 1920), so using a ribbon mic may be very desirable if you want to obtain that vocal sound.
The ribbon mics are traditionally passive designs, although there are now several active ribbon microphones in the market, like the Royer R-122.
The benefits of these ‘new’ designs are that their output level is higher, and their impedance allows them to be used with a wider range of preamps.
Regarding the third main type of mics, dynamics, although sometimes not mentioned as much for studio vocal recording, these mics shouldn’t be left out of consideration for this task. Sometimes, a dynamic microphone imprints on the voice a very desirable strength and energy.
For example, in the Kiss Sonic Boom album, Paul Stanley and Gene Simmons’ vocals were mainly recorded using a Shure SM7B.
Another example, the characteristic vocal sound of Anthony Kiedis (RHCP) is usually obtained also using an SM7B, very close, and heavily compressing the signal afterwards.
When a dynamic is used for recording vocals, the SM7 model is very popular, because it has a wider frequency response (in comparison to a ‘regular’ dynamic), but also offers the character of this type of microphone.
A comment often heard in a vocal session is “If the expensive mic is not cutting it, try an SM7. Maybe you´ll have to do some EQ, but some singers sound better in it”.
Other aspect that may help when deciding what microphone should be used with a singer is to use the frequency response of a model to counteract certain characteristics of the voice.
For example, a thin voice will benefit from a microphone with a good ‘body’, and on the contrary, a deep voice should be recorded with a model that doesn´t accentuate this aspect.
In a similar way, a very bright voice will get along better with a mic that offers a restrained mid-high response, but a dark one could use some help in this range of the spectrum.
Also, some models may accentuate the sibilance of certain singers, another decisive aspect when choosing the right mic.
So, once you know what you can expect from each kind of transducer, it is a good idea to try out several mics and let your ears be the final judge.
Starting again with the most usual, the cardioid polar pattern is probably the most used pattern for vocal recording.
On the one hand, its off-axis response allows a good amount of freedom of movement (and expressivity) for the singer, without entering into excessive tonal change.
On the other hand, the proximity effect inherent to this pattern can be used to give more/less body to the voice.
The proximity effect presents itself as an increase in the low-frequency response the closer the mic is to the source, and it is something characteristic of directional microphones (operating on pressure gradient).
Or putting it another way, depending on the distance between the singer and the mic, the bass response of this one varies, and this can be used to produce different nuances in the voice.
Nevertheless, this very same aspect may be harmful in some cases. For example, when the singer is used to performing very close to the mic, the increase in the bass response could be excessive.
Another case of a ‘bad’ side effect is when you are recording several singers with only one mic, and the distance to the mic is being used to manage the relative level of each source (the frequency response of closer/farther away voices will be altered).
If you are facing these kinds of situations, remember that each mic offers a different amount of proximity effect, so trying out a couple of them may help you resolve them.
Another way of addressing these problems would be changing to an omnidirectional pattern, because mics with this polar pattern are not affected by the proximity effect.
However, you should take into account that then you´ll be capturing more room sound, so the vocal could sound ‘farther away’ than with the cardioid pattern (even at the same distance from the mic).
A way to alleviate this side effect is by placing absorbent materials, gobos, etc. at the rear part of the microphone, so the room sound won´t reach the capsule from the back.
This kind of set-up also helps when using a figure-of-eight pattern to maximize the proximity effect of a mic (these patterns usually exhibit the most pronounced proximity effect of all), as the real lobe won´t capture room sound.
Regarding other polar patterns, like super and hyper cardioid, they are very useful to avoid spill from other sources when the vocal is being recorded with other instruments in the same room.
Valves, Solid State? Preamp?
In the first question there´s also usually some misconception, as some users believe valve mics are better than those with a solid-state circuit.
This is not true. If they´ve been properly designed and manufactured both types of mics can be equally excellent.
However, what is true is that one kind may be more appropriate for some situations than the other.
Valve mics may impart a certain colour that solid-state designs don´t. This colour is sometimes referred to as ‘smoother highs’, or ‘more body’, coming from the harmonics introduced when the valve is pushed.
The thing is, this is not good or bad, it is just a tool you may use for some kind of voices or songs. You could see it as ‘different brushes’ with which to paint the sound.
As with nearly everything related with audio, the best thing to do is to test what works best for that singer in that song.
Regarding the preamp selection, this is something similar to the type of mic you choose to use. Once you´ve decided on the mic model that best gets along with the voice you are recording, it is common to try out some models of preamp, to check which one works best for the situation.
However, one thing you may take into account when choosing which preamps to test with a certain mic, is trying to pair valve mics with ‘non-valve’ preamps and vice versa, as having this element in both steps is usually ‘too much’ (although not a golden rule).
Once you are 100% happy with the results coming from your tandem microphone-preamp, a little bit of EQ and compression may help to smooth out some details (or emphasize others).
During recording, this kind of processing is generally subtle. The objective in this stage is to introduce small improvements, leaving the heavy-handed processing for the mixing stage.
Regarding EQ, it is common to use light adjustments that will tame some undesirable aspects (voice a little honky, thin, aggressive…) or highlight some others (more body, air, presence…).
However, if you are clear about the sound you want to obtain, don´t be afraid to go for it and commit it to tape. These pieces of advice are more on the ‘cautious’ side, trying to leave open doors for the later stages in the production process.
Anyway, if you discover yourself having to equalize a lot to get rid of a problem, maybe it is time to rethink the chosen mic, preamp or distance.
Regarding filters, unless the singer has a very low range and will be reaching very low notes during the performance, usually a high-pass filter will provide some clarity, removing possible problems in low frequencies transmitted to the mic through the stand and/or cable.
In the case where you have two high-pass filters available (say, one in the mic and another in the preamp), it is usually better to use the first one to get rid of the unwanted noise as soon as possible, so it doesn´t even reach the preamp.
If you are having problems with plosive sounds even using an anti-pop filter, you could change the angle of the mic a bit, so the diaphragm is not parallel to the airflow.
Here you could aim the mic to either side of the mouth, or above/below it. In this last case, bear in mind that the sound may become, respectively, more nasal (angling up) or boomy (angling down).
This technique is also helpful when there are sibilant problems.
When making these kinds of adjustments to the position of the mic, care must be taken not to force the singer into an uncomfortable position.
Although you’ve probably seen pictures of singers recording in the studio with their chin facing up to a mic a little above their heads, this is not a good position for every singer. It is better to ask the performer how he/she is most comfortable, and go with that position.
Once the best position for the singer is clear, if you have to use a different angle for the mic because of technical reasons, you can use the anti-pop filter to cover it up.
The singer usually uses the anti-pop as a reference to his position, so you may place the filter suggesting the mic is positioned the way the singer is comfortable, but behind it the mic may be in any other position.
In these situations, attaching the filter to a different stand to the one the mic is being held with helps to arrange the filter in more ‘radical’ positions.
This also has the added benefit of reducing potential noise transmitted to the microphone via the filter (in fact, many engineers use this ‘dual-stand’ technique by default).
Regarding compression, again, it is usual to err on the safe side, with gain reductions of abut 3-6dB and attack and release times not too aggressive. The objective of compression during recording is usually that of making a subtle dynamic control, rather than achieving an obvious compression effect.
However, as will be addressed in the second part of the article, the sound committed to tape does not have to be the same as the one the singer is hearing in the cue mix... More details about compression and other techniques in the second article: Recording Vocals Part II.
Any tricks or techniques you would like to share? The comments section is all yours.