By Ángel Sampedro
Two main elements distinguish one quena from another: the diameter and the embouchure (notch, notch).
It depends on how "soft" it turns out to be.
There are different variants of diameter and woods according to sound characteristics. Larger bores (18-20mm internal) give a heavier and reinforced sound in the bass, while the finer ones (16-18mm) give an agile access to treble and overbounds, being excellent for the beginner to demand less air.
The deep notch produces more volume, but it is also harder to sound. Depending on how it is blown, the performer can slightly change the tuning of the instrument.
Explained this last acoustically, say that the flutes sound thanks to an oscillator, which consists of the air jet hitting against the edge (this is common for flutes traverses, quenas, recorders, pinkuyos, organ pipes, etc.) The frequency of each note is conditioned by the speed of the air jet and the distance between the lip and the edge. It also depends on the position of the instrument with respect to the performer's mouth. Every wind instrument has a certain "mobility" in its tuning - something that gives rise to subtleties of the touch.
Small mouthpieces have less tuning "movement", say, they modulate less, and it is easier to tone. But as a counterpart, they have less volume. A beginner can be given a small embouchure, without detriment of large players touching the recesses. One possible problem is that the narrower mouthpieces should be blown more precisely. Also, very small recesses introduce a very important constriction in the air circulation, resulting in a stretch of the octaves (very high acute notes)
As a general rule, a larger internal diameter quena will require more air from the performer, and will obtain greater volume. A deep notch will determine the same.
The inclination of the end with respect to the line of the quena, the angle and position of the notch or notch with respect to the wall, also influence the ease of execution.
The ease in the execution of the notes is also conditioned by the shape of the tube and its "harmonicity" (that is, how the different modes of vibration cooperate to form the sound). The evaluation of this aspect, especially in high quality quenas, is a specific and indispensable work of the luthier.
The different performers can feel more comfortable with one type or another of notch, being the most common in V, U and occasionally square. The size of the notch relative to the diameter and conicity of the quena is also an important factor when constructing the instrument.
In our opinion, the wide U-shaped notch is the one that contributes most to a wide dynamic range and volume, as well as good tuning. The explanation is that much of the sound volume of the quena comes from the notch, which, having a larger area, will favor it. The U shape of our mouths, in addition, makes the edge is not too far from the performer's lip, avoiding the "hardening", and being wide, makes the precision of the blow is not extreme.
Another important factor is the good completion and conception of the instrument. An instrument without sharp angles, no roughness or aggressive parts, is much more ductile in good hands. Quenas are usually seen well finished in sight, with bright luster, but do not take into account the part of the instrument that is in contact with the face of the performer, with right angles that short or long, hinder good execution.
Finishing holes and ends
A good hole finish is not only more comfortable, but it also prevents the instrument from future problems. In a bamboo, the greatest exchange of moisture occurs longitudinally, since the ducts carrying sap flow in that direction. Therefore, to guarantee the duration of the instrument, it is advisable to isolate said parts and thereby delay the exchange of humidity.
Our quenas are sealed by immersion. Therefore, the interior of the instrument is protected. This sealing does not prevent the bamboo from breathing, but slows down the exchange of moisture. In some cases, we also lacquer the inside of the tube, further restricting the humidity
This sealing or lacquering also has an acoustic effect. There are different opinions about the contra and benefits of the internal treatment of the tube. We consider that it is not a very important factor, and in no way negative. Plus, the seal tends to cover small pores in the wall that exert a friction (resistance) on the movement of the air. In practice, we observe differences between the same quena tested before and after having been sealed. The result is greater clarity of sound and volume, as well as a more spontaneous response. The phenomenon is similar - although on a smaller scale - to that observed on a flute whose interior is dirty. Once clean, it changes both in volume and loudness. It is also similar to the fact of oiling the inside of a recorder - although on this last point there are also great discussions.
Then, the holes and ends are individually lacquered
The mouthpieces made with a hardwood incrustation help to preserve the part of the quena with greater contact with humidity