Optimization of a newly developed carillon

© Fraunhofer IBP

Measurement of the signals performed at the carillon model, with adjacent cavities being covered.

© Fraunhofer IBP

Acoustic tests carried out at the carillon model in the test laboratory.

In close cooperation with the instrument builder SCHIEDMAYER CELESTA, the researchers at the Fraunhofer Institute for Building Physics IBP investigated how to optimize the sound of a newly developed manual carillon. One of the characteristics of a perfected musical instrument is the pitch of each individual tone that changes, but not its timbre. This creates the overall sound being perceived as pleasant and harmonious by the audience.

The sound plates of the new instrument met the ambitious objectives only in the medium tonal range. While the decay time of the high pitches was too short, the fundamental tone of the low pitches could not be excited sufficiently due to the large mass of the sound plates.

The modifications had to meet two special requirements: Firstly, the width of each sound plate was to remain the same, as otherwise playing the instrument would have become more difficult. Secondly, the plates had to be of a minimum thickness to ensure that the short plates producing the higher pitches were not moved from their original positions while playing.

To ensure that the sound characteristic of high pitches, both with regard to sound intensity and sound decay, does not differ significantly from the sound characteristic of low pitches when listening, measurements, theoretical models and constructive ideas were related. The practical application of the mathematical formulas particularly aims at a significantly more exact dimensioning of the resonators. Furthermore, the research activities were focused on the sound spectrum and the decay behaviour in dependence of material and mass of the hammer, in order to gain knowledge for suitable design principles.