Convex Dome Research Articles

Sound radiation from an axisymmetric radiator in an infinite baffle

A method that can be applied to the radiation problem of a convex or a concave radiator in an infinite baffle is described. This method utilizes the least‐square‐error method, and allows the radiator to take almost any kind of axisymmetric shape even though the accuracy of the result depends on the shape. The frequency responses of the on‐axis sound pressure are calculated for three cases of the radiator shape, a convex dome, a concave dome, and a combination of a truncated concave cone and a convex dome at the center. The accuracy is confirmed by comparing the results obtained by the present method with those obtained by previous methods [Hideo Suzuki and Jiri Tichy, J. Acoust. Soc. Am. 69, 41–49 (1981)]. Three error indexes are suggested for an estimation of the accuracy of the results.

Sound radiation from an axisymmetric radiator in an infinite baffle.

A method that can be applied to the radiation problem of a convex or a concave radiator in an infinite baffle is described. This method utilizes the least square error method, and allows the radiator to take almost any kind of axisymmetric shape even though the accuracy of the result depends on the shape. The frequency responses of the onaxis sound pressure are calculated for three cases of the radiator shape, a convex dome, a concave dome, and a combination of a truncated concave cone and a convex dome at the center. The accuracy is confirmed by comparing the results obtained by the present method with those obtained by previous methods by the present authors. Three error indexes are suggested for an estimation of the accuracy of the results.

Sound radiation from convex and concave domes in an infinite baffle

The sound radiation from convex and concave rigid diaphragms represented by portions of a spherical surface was investigated for the purpose of modeling a direct radiator loudspeaker. Pressure responses, radiation impedances, directivity patterns, and some other characteristics were obtained and compared with those of a circular flat diaphragm of the same radius. While the on axis pressure response of the rigid flat piston remains constant, the response of the convex dome decreases for about ka?1.0 as the height of the dome increases. The concave dome has a wide smooth peak around ka=1.5 and several peaks and dips for larger values of ka. The radiation resistance of the convex dome increases by the rate of 12 dB/oct or less up to ka=2.0 and remains constant in the higher frequency regions. On the other hand, the radiation resistance of the concave dome has its largest peak at the frequency corresponding to the peak of sound pressure response. The directivity patterns of either the convex or concave dome do not have minima with zero sound pressure and their radiation patterns are generally wider than those of the circular plate. All these results are well explained by the energy flow and pressure distribution near the radiator.

Sound radiation from convex and concave domes in an infinite baffle

The sound radiation from convex and concave rigid diaphragms represented by portions of a spherical surface was investigated for the purpose of modeling a dome loudspeaker. Pressure responses, radiation impedances, directivity patterns, and some other characteristics were obtained and compared with those of a circular flat diaphragm of the same radius. While the on‐axis pressure response of the rigid flat piston remains constant, the response of the convex dome decreases for about ka ≥ 1 as the height of the dome increases. The concave dome has a wide smooth peak around ka = 1.5 and many peaks and dips for larger values of ka. The radiation resistance of the convex dome increases by the rate of 12 dB/oct or less up to about ka = 2.0 and remains almost constant in higher frequency regions. On the other hand, the radiation resistance of the concave dome has its largest peak at the frequency corresponding to the peak of sound pressure response and shows many peaks and dips in higher frequency region. The radiation reactance of the convex dome is smooth and always positive, while the concave dome also exhibits negative reactance due to the resonance in its cavity. The directivity patterns of either the convex or concave dome do not have minima with zero sound pressure and their radiation patterns are generally wider than those of the circular plate.