Acoustics of baroque, classical and modern flutes

modern flute
B foot

E6

Music Acoustics UNSW

modern B modern C classical C classical D classical flared baroque B3 B3
C4 C#4 D4 D#4 E4 F4 F#4 G4 G#4 A4 A#4 B4
C5 C#5 D5 D#5 E5 F5 F#5 G5 G#5 A5 A#5 B5
C6 C#6 D6 D#6 E6 F6 F#6 G6 G#6 A6 A#6 B6
C7 C#7 D7 D#7 E7 F7 F#7 multiphonics

No Split-E Mechanism

Impedance

Fingering
a key depressed
a key not depressed
a part of the mechanism that is not normally touched
Details in fingering legend.

Acoustic schematic
a closed tone hole
an open tone hole

Non-specialist introduction to acoustic impedance
Non-specialist introduction to flute acoustics


Impedance spectrum of a modern flute with a B foot measured at the embouchure hole using conventional fingering for E6 without a split-E mechanism. Z is plotted in dB, i.e. 20 log(Z/Pa.s.m-3).

The standard fingering for E6 produces two different acoustic configurations (see diagram), depending upon whether or not the instrument has a 'split E' fingering mechanism. This is a clutch whereby the RH second finger closes one of the G# holes.

For the flute without a split E, should one think of this fingering as E4 with a double register hole, or a cross-fingering which slightly flattens A4 and A5, and flattens A6 somewhat more? If we compare this graph with that for A4, we see a strong similarity, whereas the similarity with that for E4 is rather less. In the graph for E6, the third large minimum produces E6. The first two produce ~A4 and ~Ahalf flat5. (The very small minimum near 1.2 kHz is unplayable.)

Note that, because of the acoustic similarity between this fingering and that for A5, it is difficult to slur between A5 to E6 on such a flute. With the split E mechanism, there is only a single open hole, which has effects discussed below.

Sound


Sound spectrum of a modern flute with a B foot played using conventional fingering for E6 without a split-E mechanism.

Note here the two irregularities in the broad band curve at ~A4 and ~Ahalf flat5, excited at the rather strong minima at these frequencies.

Sound Clip

You can hear E6 without a split-E played with conventional fingering by Geoffrey Collins.

Split-E Mechanism

modern flute B foot

Impedance

Fingering
a key depressed
a key not depressed
a part of the mechanism that is not normally touched
Details in fingering legend.

Acoustic schematic
a closed tone hole
an open tone hole

Non-specialist introduction to acoustic impedance
Non-specialist introduction to flute acoustics


Impedance spectrum of a modern flute with a B foot measured at the embouchure hole using alternative fingering for E6 with a split-E mechanism.

For the flute with a split E, should one think of this fingering as E4 with a single register hole, or a cross-fingering which slightly flattens A4 and substantially flattens A5 and A6? If we compare this graph with that for A4, we see a reasonable similarity at low frequency, but the similarity with that for E4 is rather less. In the graph for E6, the third large minimum produces E6. The first two produce ~A4 and ~Ab5. The higher harmonics of these two low notes have no support from impedance minima (they are diffuse timbres) and so they are not very stable. (The fourth large minimum plays a flat D7. The small minimum near 1.1 kHz is unplayable.)

Note that, because of the substantial acoustic differences between this fingering and that for A5, it is relatively easy to slur between A5 to E6 on such a flute. The single open hole acts somewhat like a register hole. Without the split E mechanism, there are two open holes, which have effects discussed above.

Sound


Sound spectrum of a modern flute with a B foot played using alternative fingering for E6 with a split-E mechanism .

For this sound spectrum, there are no similar irregularities in the spectrum corresponding to the first two minima.

Sound Clip

You can hear E6 with a split-E played with alternative fingering by Geoffrey Collins.

E6 with donut

modern flute B foot

Sound


Sound spectrum of a modern flute with a B foot played using fingering for E6 with donut.

The donut (sic) is a metal insert that partially occludes one of the G# holes. It is sometimes fitted to flutes without split E mechanisms, and it reduces the size of the hole used as an unnecessary register hole for E6. Because the other G# hole is used to play G#, this does not affect intonation for that note, although it does make some difference to the timbre of A5/6.

Sound Clip

You can hear E6 with donut played by Geoffrey Collins.



The Virtual Boehm Flute may suggest other fingerings for this note.
Fingering legend
How were these results obtained?
Acoustic measurements are available for these flutes -
modern B, modern C, classical C, classical D, classical flared, baroque
Sound clips are available for modern B, classical flared and baroque
To compare flutes, it is easiest to open a separate browser window for each instrument.

Copyright © Academic Press. JSV+ Joe Wolfe, John Smith, John Tann and Neville H. Fletcher, Acoustics of baroque, classical and modern flutes
Revised to include the baroque flute 2001.