Design Philosophy

The development of a new type of endblown flute was motivated by the need for an 'ethnic-sounding' instrument that was both in tune was itself (correct intonation) and could be tuned accurately to concert pitch. Most endblown flutes (and many penny whistle-type instruments) available from music stores are little more than toys in that it next to impossible to play them in tune with themselves or with anyone else.

The EndBlown Flute range is the result of a number of years playing and experimenting with endblown flute designs. The flutes were initially made to meet a personal need, but due to demand from friends and colleagues a limited number of instruments are being made for sale.

Tone Quality

Initial prototypes were made from PVC conduit since it was easy to work. The first lesson learnt was that the material the flute is made from has almost no impact on the sound of the flute (you try telling James Gallway that!).

The fundamental parameter controlling the tone quality, useful range and intonation of a flute is in fact the bore to length ratio. Decreasing the bore to length ratio improves the tuning between octaves, increases the upper range limit and produces a richer tone. However decreasing bore to length ratio also reduces the maximum volume at which the instrument can be played and makes the lower notes difficult to sound. The other parameter affecting tone is the size and shape of the blowing hole. A larger blowing hole produces a louder, but less focused sound and tends to adversely affect the intonation. It is also much harder to play a flute with a large blowing hole. If the blowing hole is too small, the sound becomes weak and it is hard to play expressively.

Tone Hole Placement

Given an appropriate blowing geometry and tube bore to length ratio, the next task is to chose the size and location of the tone holes to achieve an optimum tradeoff between acoustic accuracy and the demands of the human hand. Whilst the the approximate position of the holes can be predicted from analysis of the standing wave patterns inside the flute, the actual task of getting the holes exactly in the right place requires extensive trial and test. The rule of thumb used is that increasing the size of a hole reduces the pitch whereas moving the hole further up the instrument increases the pitch. The normal procedure is to start at the bottom of the instrument and work upwards, a hole at time. This is necessary because the note sounded depends to some extent on all the open holes on the instrument, not just the size and location of the upper most open hole.

For the low D flute, the acoustically optimal tone hole placement leads to a spacing too wide for a comfortable hand position. To reduce the required stretch, the bottom tone holes are made smaller than ideal such that they can be located further up the instrument. This leads to a rather stuffy sounding bottom E on these flutes. The hand constraints are not an issue for the smaller flutes and fairly large tone holes may be used.

Tuning to Concert Pitch

Due variations in air temperature, air humidity and the player's preferred embouchure, the absolute pitch of the flute may vary by up to +/- 50% of a semitone, which is more than what can be compensated for by 'lipping' the note up or down. For this reason, the flutes are provided with a sliding joint between the blowing hole and the first tone hole. Pulling out the head joint lowers the pitch and pushing it in raises the pitch. However it must be remembered that this type of adjustment affects the upper notes in each octave more than the lower notes.

End blown flutes