Producing a good tone on low flutes takes practice, and, like all aspects of playing low flutes, it is helpful to make modifications from what you would do on the C flute.

Air
Lower flutes use more air than the C flute, so developing good breathing habits is essential. See part 6 for breathing tips.

TIP: use lots of air at slow speeds
On low flutes, the air speed must be slower than on the C flute, and relatively even in each octave. The speed increases slightly between the low, middle and high registers, but novice players often over-compensate for this and produce cracked notes in the middle register and an overly sharp high register. To create a slow air speed, keep the aperture a little wider than on the C flute and make sure the inside of the mouth and throat are open wide. Don’t push too hard with the support muscles and allow the body to resonate.

Embouchure
Many people believe that low flutes should be played with a relaxed embouchure. To an extent this is true, but firm control from the middle of the embouchure is essential for the correct placement of air, and great flexibility is also required for the control of tone colours (see part 5). Consider how the embouchure works on the C flute. It is a misconception that the embouchure has to work harder as the pitch goes up, and excessive embouchure tension in the high register often causes players to ‘blow raspberries’. In fact, it is possible to create a sound in the high register just with the correct air speed and a very relaxed embouchure, and the purpose of the embouchure is purely to direct the air into the optimum place. This means that the embouchure muscles actually work hardest in the low register, as the air has to be directed more downwards into the flute. The same is true on low flutes. The increased size of the instrument means that the air generally needs to go a little more into the instrument than on the C flute, so the muscles need strength in order to do this. Playing with a too relaxed embouchure (and sending the air too high) over the lip plate) is one of the main causes of sharp pitch in low flute playing

Flute position
As the size of the flute increases, the position of the flute on the lip also changes. Again, consider what happens on the C flute. Ideally, around a third of the flute’s embouchure hole is covered by the bottom lip. The same is true of the alto and bass flute, but as the apertures are bigger, the instrument needs to be placed a little lower on the chin to create the best sound. Again, incorrect flute placement on the bottom lip is another of the main causes of sharp intonation on the alto and bass flute.

Resonate
Resonance is incredibly important in the production of tone on low flutes. Exercises such as throat tuning (see Robert Dick: Tone Development through Extended Techniques for a full explanation of this) are extremely helpful in the creation of a rich, full tone. If you are resonating correctly, you will feel the instrument vibrate slightly in your hands. This is, for me, one of the best aspects of playing low flutes, as you can feel completely connected to the instrument and its sound. To achieve this, keep all the internal upper body cavities (mouth, throat, head, chest) as open as possible. Good posture is essential for this, and allow the support muscles to be strong while keeping everything above them open and relaxed.

High Register
Low flutes are made with a bore size that is generally suited to a rich tone in the low register. As a result, it is to be expected that the difference in tone between the registers will be greater than on the C flute, which is made with a bore suited to evenness across the registers. Novice players often force the tone in the high register in particular to make it sound like a C flute, but no amount of pushing the air will create that type of sound, as the harmonics are not strong enough in the sound. Instead, embrace the high register tone for what it should be on low flutes; less penetrating and sweeter than on the C flute, and possibly also with a little more air in the tone.