| Popis: |
The saxophone is a musical instrument which was created in the nineteenth century by Belgian inventor Adolphe Sax. It has since become a popular and versatile instrument used in various genres of music, including jazz, classical, and pop music. The mouthpiece and reed play a crucial role in this versatility as they significantly impact playing behaviour and sound. Even subtle changes in these parts (order of magnitude micrometres) can cause significant differences in the playability and sound of the instrument. It is challenging to categorize reeds and mouthpieces in objective terms, and no clear set of parameters is available to classify and compare them. Until now, mouthpieces are mainly categorized by tip opening (the space between the reed and the tip of the mouthpiece), facing length and internal shape. However, it is difficult to compare the artistic and acoustic performances of mouthpieces objectively. Musicians have to go through a lengthy process of trial and error before finding the right mouthpiece that suits their playing style and sound. In this thesis, several aspects of these challenging problems were investigated to better understand saxophone reed dynamics and the influence of mouthpiece design. On the level of apparatus development, the work resulted in a system which allows a fully automated measurement of reed vibrations and saxophone sound over all relevant settings of lip force, lip position, blowing pressure and notes. The apparatus made it possible to obtain full-field and time-resolved measurements of reed position and reed strain during the vibration cycle. The results showed that when the reed touches the mouthpiece, significant transversal strain develops, and the reed bends in the transversal direction so that its centre is below the level of the side rails. New parameters were determined to define the combinations of lip force and blowing pressure for which the instrument will produce sound. With these parameters, a so-called playability range of different mouthpieces could be described objectively. The effect on the playability of even subtle design differences could be quantified. |
