Acoustic radiation and diffraction from convex and concave domes
Abstract
The effects of the diaphragm shape of a loudspeaker on the radiation and diffraction characteristics are discussed using convex and concave domes in an infinite baffle. The least square error method, one of the weighted residual methods, is employed as the mathematical tool for the solution of the problems. The results show that these characteristics are highly dependent on the shape of the diaphragm, even if it vibrates like a piston. The response of the concave dome has a wide peak due to the cavity resonance, resulting in higher radiation efficiency. The convex dome has lower onaxis pressure response in the same region due to the dispersion of energy to the offaxis direction. The diffraction of sound from a concrete ring source by the convex and concave domes is also investigated in order to discuss the interaction between the loudspeaker units of a complete system. The convex dome has much larger diffraction effects than the concave dome, especially in the highfrequency region. It is shown that even the concave dome produces a discernible amount of amplitude distortion of sound radiated from an adjacent source. The radiation and diffraction phenomena are well explained by the use of a graphical representation of the energy flow and pressure distribution.
 Publication:

Ph.D. Thesis
 Pub Date:
 March 1981
 Bibcode:
 1981PhDT........21S
 Keywords:

 Concavity;
 Convexity;
 Diffraction Patterns;
 Domes (Structural Forms);
 Sound Waves;
 Error Analysis;
 Least Squares Method;
 Loudspeakers;
 Weighting Functions;
 Acoustics