Sound radiation from Caribbean steelpans

Abstract

Besides radiating sound from the note area being struck, a steelpan radiates from neighboring note areas that vibrate sympathetically, from the areas between notes, and from the skirt [Rossing et al., Phys. Today 49(3), 24-29 (1996)]. Measurements were taken in an anechoic chamber using a four-microphone intensity probe to visualize the acoustic radiation from selected notes on a double second and a low tenor steelpan. Swept sinusoidal excitation was effected using an electromagnet. Sound intensity maps were drawn for the first three harmonics.

Contour scanning laser vibrometry characterization of Caribbean steelpan

“…The remarkable tuning process is able to produce this integer sequence of mode frequencies despite the 4 th order nature of the governing equation [10]. This phenomenon has been reported previously by Rossing and Copeland [7,8] . The phenomenon can be observed in the measured data by location of matching resonant frequencies in the spectra of individual note areas.…”

“…Holographic interferometry [6][7][8] has been used extensively to study the vibrational mode shapes. Achong's analytical model of steelpan vibration is supported by contact velocity measurements with authentic impact excitation.…”

Sound radiation from Caribbean steelpans using nearfield acoustical holography

“…3 in the paper by Copeland. 1 Note excitation was obtained by driving the electromagnet at the test frequency from a signal generator through a power amplifier with the necessary current drive. The signal generator used was part of an Ono Sokki FFT analyzer.…”

“…Additional partials extend the upper frequency range to above 3000 Hz giving an overall tonal range comparable to that of a grand piano. 1 Individual instruments contain from 3 notes, in the case of a bass steelpan to 32 notes arranged in three concentric rings in the case of a soprano tenor pan. The particular instrument used in this study was a low C tenor containing 29 notes designed manufactured and tuned by Bertrand Kelman, an acknowledged maker and tuner in the steelpan fraternity.…”

Acoustics of percussion instruments: An update

“…While the active intensity is the most significant field in a concert hall, both active and reactive intensity fields have to be considered in recording a steelpan. Figure 9 shows a map of active and reactive sound intensity in a plane that bisects a double second steelpan when a single note (F]3) is excited at its fundamental frequency [18]. pg1 pg2 pg3 pg4 pg5 pg6 pg7 pg8 pg9 pg10 pg11 pg12 pg13 pg14 pg15 pg16…”