Combining modes of passion
23 Apr 2013
I started playing the kantele when I was five. When the time came, I chose the path of physics at the university. For some time, I had been wondering how to combine these two passions. Turned out that the analysis and synthesis of musical instruments is something where they would meet.
At this very moment, there are many teams working on physics-based modelling of musical instruments. The aim is not only to understand how they work, but also bring new tools for composers and instrument builders. Particularly, the modelling methods offer a chance of exploring instruments before and beyond building physical copies.
I was lucky enough to meet Jyrki Pölkki , an instrument builder at Soitinrakentajat AMF with a passion to make acoustically improved instruments. He had many copies of instruments in his workshop in Leppävirta, in which he had tried some new ideas. One of these was a kantele with a new kind of body – like two boats facing each other. Nowadays, this modified kantele is sold commercially under the name of Kirjokansi.
This kantele had proven to be louder than the traditional kanteles in the measurements conducted in the anechoic chamber of the Department of Signal Processing and Acoustics at Aalto University. My mind was set to understand why. In my thesis, I made a finite element model of the kantele and studied its vibrational modes and sound radiation. An example of a vibrational mode is shown in the picture above. The red areas depict vibration maxima whereas in the blue areas, there is very little vibration.
A string instrument body is an essential amplifier to the string vibration, so that we can actually hear the instrument. In this modified kantele, the top plate can vibrate freely, just like in the traditional carved kanteles. In addition, the back plate encloses air inside the kantele, which also vibrates, just like in the box kantele. Consequently, the modified kantele incorporates both the carved and the box kantele. Thus, the modified kantele amplifies the string vibration better than the traditional kanteles, and we hear a louder instrument.
Come and experience the kantele at the exhibition!
ps. Some musical instrument acoustics teams for those interested:
Audio signal processing research group at Aalto:
Acoustics group at the University of Edinburgh: