Formant Tuning Primer for Men

I’m planning to do a few articles this summer about formant tuning techniques for men. I don’t want to write a full explanation in each article though, so I’ll refer back to this one.

My Formant Tuning Bullet Points

Here’s a brief-ish rundown from me:

• • Any sung pitch is actually a variety of sounds. There’s the periodic tone from the sung pitch, comprising the fundamental and the harmonics, and then there’s a little non-periodic noise mixed in from air movement. These sounds combine to give you pitch and timbre.
  • A pitch has a fundamental frequency measured in hertz (Hz for short), and then the overtones (which we’ll call “harmonics“) are integer multiples of that frequency (Hx, ie. H1 H2 H3 H4 etc.). For example, the second harmonic will often be referred to as H2.
  • Formants are resonances, and for singers they’re based on the shape and size of the vocal tract, which includes your tongue, lips, soft palette, jaw position, and relative depth of your larynx. When looking at spectrum charts (such as those included in this article), I think of formants as resonance “zones”, and those zones allow the full resonance of the harmonics that reside within them, while harmonics that don’t fall in the range of a formant are weakened.
  • The first two formants (F1 and F2) and the relationship between them make up vowels. Brush your teeth and move your mouth and tongue around, and you’ll hear the formants changing frequencies based on the shapes you make.
  • A couple general-purpose concepts for tuning the formants are:
    • A longer vocal tract means lower first and second formants. Stick out or round your lips and drop your larynx, and the formants will drop.
    • A shorter vocal tract tends to raise the formants. Drop your jaw, spread your lips or raise your larynx to do this.
    • The tongue influences the second formant more than the first. Forward tongue = higher second formant. Rolled back tongue = lower second formant. Up to a point, the first formant moves counter to the second formant when tuning with the tongue.
  • We naturally match harmonics to formants when speaking. When singing we need to do it deliberately. Why? Three reasons:
    • By prioritizing specific harmonics, opera singers can be more easily heard through an orchestra without requiring unhealthy levels of breath pressure.
    • As we sing higher, it becomes harder to match any overtones (Hx) to formants (Fx). This is because the frequency distance between harmonics increases, but the formants affect the same frequency ranges as before.¹ See the video below:
    • I personally also find the results more beautiful sounding. The dominant harmonic has a tonal purity that works very well in classical music.
  • Here’s an example video visualizing the challenge. The x-axis represents the frequency (higher as you go further right), and the y-axis represents amplitude (taller is louder):

• Did you notice how the harmonics (the pointy peaks) got more distant from one another as my voice went higher? For practice, pick a harmonic and follow it as best you can.
  • How far did it move relative to the fundamental (H1 for short, and it’s the left-most pointy peak).
  • Did you notice that there were spots along the x axis where all the harmonics appeared louder as they moved through it? Those are where the various formants are.
  • Did you notice there were spots where individual harmonics became noticeably weaker? That’s where the harmonic doesn’t match up with a formant.
• The passaggi are where we have to change our formant/harmonic-matching strategy, or we risk distorting our vocal tracts and the resulting sound to try and track a disadvantageous harmonic higher.
• These strategies are sometimes called “vowel modification” or “formant tuning”.
• The more difficult and higher passaggio – the secondo passaggio – requires men to emphasize the second formant, which is an alien feeling since most of our speech strategies rely on the first formant.
• So we have to practice. :)

Here’s a breakdown of the strategies at different parts of the voice:

• In the lower voice, F1 and F2 match easily with individual harmonics or even several harmonics. There’s no need to focus on formant tuning.
• Immediately below the primo passaggio, F1 tends to match up with H3 for most vowels. Again, it’s not a difficult pairing to do.
• Above the primo passaggio, open vowels (“ah”, “eh”) tend to pair F1 with H2. This has a call-like quality, and it’s very powerful. Beginning male singers often struggle here by raising their larynx.
• At the primo passaggio closed vowels like “ee” and “ooo” switch to second formant tuning.
• Above the secondo passaggio (usually about a perfect fourth higher than the primo passaggio), the second formant (F2) is paired to the third or fourth harmonic depending on the vowel. This is not the only strategy, but it’s one that has been used by many great singers. It’s also surprisingly tricky.
• Computer software is useful to visualizing these strategies, but with practice, it is possible to hear the primary harmonics distinctly without a computer.

Women have their own set of issues (the middle voice is where F2 tuning happens, for example), but I probably won’t write much about it because I don’t have much personal experience in my own singing (duh) or working with students on it. That may change in the future, but for now, I’ll have to focus on men.

Regardless of your sex, if you find this interesting, the absolute best resource is the book Resonance in Singing by Donald Miller. It’s full of examples for men and women, alongside discussions for how to achieve solid formant tuning. Here’s his first chapter to whet your appetite:

Pavarotti: King of Second Formant Tuning

“Be Careful, Wotan, Be Careful”

A few warnings are in order. None of this is a replacement for good singing technique. Everything having to do with breath and posture and good body use are still necessary when practicing formant tuning. This is an additional thing to practice on top of all of that. In fact, second formant tuning has an annoying way of not working at all without the rest of your technique lined up.

The singer’s formant is still important even if you follow this. The prominence of the singer’s formant will depend on your voice and what kind of rep you sing, but in general some singer’s formant throughout one’s range communicates “opera singing” and always helps with audibility. Technically, the singer’s formant is a type of formant tuning, but it’s not through the vowel producing first and second formants, so I think of it having its own technique.

This stuff is dense. If you don’t understand a concept, then come back to it later. I know we bloggers are supposed to write stuff that is easily digestible through a first read-through, but this subject won’t work like that. I have been thinking about these issues for years and practicing them, and there’s still more to learn.

Also, don’t think that you’re suddenly going to have a much larger voice by doing this. This can help make you louder, yes, but it’s not going to fundamentally transform your voice into Mario del Monaco’s or George London’s. It will however give you a strategy that emphasizes both beauty and vocal safety at difficult parts of the voice.

1. This is because the harmonics are multiples of the fundamental. So if you have a fundamental pitch at 100 Hz, the harmonics will be 2 x 100 and 3 x 100 and so on. But can you work out what happens as the fundamental pitch gets higher?