Acústica de los órganos de tubulares y tendencias futuras en la investigación

Scientific explanations for having a better understanding of the operation of pipe organs, and revision of some common beliefs regarding their building, seeking to improve this art, are presented in this work.En este trabajo se presentan explicaciones científicas para tener un mejor entendimiento de cómo funcionan los órganos tubulares y revisar algunas creencias comunes en su construcción, buscando mejorar este arte

Simulation of mallet percussion instruments by a coupled modal vibroacoustic finite element model

A three-dimensional coupled vibroacoustic finite element model for physics-based simulations of sound generation by mallet percussion instruments in the time domain is discussed in the present paper. The mechanical model takes the orthotropic material properties of the wooden sound bars and the nonlinear nature of the interaction force between the mallet head and the sound bar into account while the acoustical model considers radiation into an unbounded domain. A direct coupling of the sound bars, acoustical cavity resonators, and the excitation by a mallet is considered with exploiting the modal basis to reduce the number of degrees of freedom of the system. Both the mechanical and the acoustical models are validated by comparing them to measurements performed on an Orff xylophone. A case study shows the capabilities of the coupled model, including the analysis of the energy balance, the effect of tuning the resonator, and the excitation of the torsional modes of the sound bar

Properties of the Sound of Flue Organ Pipes

This chapter is an overview of the characteristic sound properties of flue organ pipes. The characteristic properties of the stationary spectrum and attack transient have been surveyed and assigned to properties of the physical systems (air column as acoustic resonator, air jet as hydrodynamic oscillator, and pipe wall as mechanical resonator) involved in the sound generation process. The measurements presented underline the primary role of the acoustic resonator in the stationary sound and of the edge tone in the attack

The influence of pipe organ reed curvature on tone quality

Although organ flue pipes have been widely studied, the same claim cannot be made for pipe organ reed stops. Given certain design constraints, such as the type of reed stop being voiced and the desired tone quality, the reed voicer must use consummate skill to curve the reed tongue so as to produce the best and most stable tone as well as to guarantee that each pipe blends with its neighbors. The amount and type of curve given to a reed tongue influences not only the harmonic structure of the steady-state sound but also the attack. There are two fundamentally different types of curvature that can be given to a reed tongue, the trompette (chorus reed) curve (which gives a bright sound) and the smooth-toned curve employed for clarinet pipes. This study investigated the effect of reed curvature on the vibration and tone (as assessed by professionals) on reed tongues of both types. Two F2 (8'F, 87.3 Hz) pipes (a trompette and a clarinet) were constructed and voiced with differently curved tongues to produce a variety of tones. The vibration of the reed tongue was measured under typical conditions by laser vibrometer; the pressure waves in the boot and in the shallot were measured by means of one-quarter inch microphones, and the pipe's sound was recorded at the egress. By performing various measurements simultaneously, phase differences were also determined, the extreme sensitivity of tone to reed curvature was demonstrated, and a recently proposed theory of reed vibration was shown to be more accurate than the standard model