Análise dinâmica aplicada à pratos de percussão de diferentes ligas de bronze

Abstract

Cymbals are ancient musical instruments that after various types of applications became fundamental equipment for drummers. The many variables that influence the final sound results in a great sound complexity and, represents the huge range of sounds that can be obtained. In order to study, characterize and differentiate cymbals from dynamic analysis methodologies, three samples with different bronze compositions (CuSn8, CuSn10 and CuSn20) were selected. To validate the use of these choices, their curvatures were measured using a dial indicator adapted on a table with adjustable advance. In addition, the edge thicknesses were collected at eight diametrically opposite points with the aid of a caliper. A precision scale was used to obtain their weight. Thus, the similarity of the results was responsible for the validation. By subjecting them to recording to capture their sounds, it was possible to obtain their respective signals in time. Then, an analysis of the frequency domain signals was performed using the Fast Fourier Transform (FFT), as well as a comparison of ten statistical indicators for each material (Peak, Mean, Mean Square, Root Mean Square, Variance, Standard Deviation, Skewness, Kurtosis, Crest Factor and K Factor). Although such analyzes have allowed discriminating cymbals compositions from the deterministic point of view, the same can not be said for probabilistic analysis.