Beamforming on the icosahedral loudspeaker (IKO), a compact, spherical loudspeaker array, was recently established and investigated as an instrument to produce auditory sculptures (i.e., 3-D sonic imagery) in electroacoustic music. Sound beams in the horizontal plane most effectively and expressively produce auditory objects via lateral reflections on sufficiently close walls and baffles. Can there be 3-D-printable arrays at drastically reduced cost and transducer count, but with similarly strong directivity in the horizontal plane? To find out, we adopt mixed-order Ambisonics schemes to control fewer, and predominantly horizontal, beam patterns, and we propose the 3|9|3 array as a suitable design, with beamforming crossing over to Ambisonics panning at high frequencies. Analytic models and measurements on hardware prototypes permit a comparison between the new design and the IKO regarding beamforming capacity. Moreover, we evaluate our 15-channel 3|9|3 prototype in listening experiments to find out whether the sculptural qualities and auditory object trajectories it produces are comparable to those of the 20-channel IKO.

二十面体扬声器 (IKO) 上的波束成形是一种紧凑的球形扬声器阵列，最近被建立并研究作为一种在电声音乐中产生听觉雕塑（即 3-D 声波图像）的工具。水平面中的声束通过在足够近的墙壁和隔板上的横向反射最有效和最具表现力地产生听觉对象。是否可以以大幅降低成本和换能器数量的 3D 打印阵列，但在水平面上具有同样强的方向性？为了找到答案，我们采用混合阶 Ambisonics 方案来控制较少的、主要是水平的波束模式，我们建议将 3|9|3 阵列作为合适的设计，将波束成形交叉到高频的 Ambisonics 平移。硬件原型的分析模型和测量允许在波束成形能力方面对新设计和 IKO 进行比较。此外，我们在听力实验中评估了我们的 15 通道 3|9|3 原型，以确定它产生的雕塑质量和听觉对象轨迹是否与 20 通道 IKO 的相似。