Ma Xiaohui, Hegarty Patrick J, Pedersen Jan Abildgaard, Larsen Jakob Juul
Dynaudio A/S, Sverigesvej 15, Skanderborg, 8660, Denmark.
Amazon Lab126, 1100 Enterprise Way, Sunnyvale, California 94089, USA.
J Acoust Soc Am. 2018 Jan;143(1):51. doi: 10.1121/1.5019476.
Personal sound zone systems aim at creating multiple listening zones within a shared space with minimum interference between zones, but the performance is often poorer than simulations predict and effects of nonlinear distortion are sometimes audible. This paper assesses the impact of nonlinear distortion on sound zones through simulations and measurements performed under anechoic conditions. Two sound zones, one bright and one dark, are created with acoustic contrast control using two loudspeaker arrays driven at 250 Hz. Nonlinear distortion is modelled using second or third order nonlinearities. Simulations show that nonlinear distortion degrades the acoustic contrast, which is confirmed by experimental measurements. The harmonic distortion is audible in the dark zone. Frequency resolved measurements reveal that harmonic distortion contributes to contrast loss, but nonlinear effects on the fundamental component are the main cause. Nonlinear distortion can be controlled through regularization of the loudspeaker control effort. Simulations and experiments show an optimum regularization range where contrast is optimized by balancing linear performance and nonlinear distortion.
个人声区系统旨在在共享空间内创建多个聆听区域，使各区域之间的干扰最小化，但实际性能往往比模拟预测的要差，而且非线性失真的影响有时是可闻的。本文通过在消声条件下进行的模拟和测量，评估非线性失真对声区的影响。使用两个以250Hz驱动的扬声器阵列，通过声学对比度控制创建了两个声区，一个明亮区和一个暗区。使用二阶或三阶非线性对非线性失真进行建模。模拟结果表明，非线性失真会降低声学对比度，实验测量结果证实了这一点。暗区内可听到谐波失真。频率分辨测量结果表明，谐波失真会导致对比度损失，但对基波分量的非线性影响是主要原因。可以通过对扬声器控制力度进行正则化来控制非线性失真。模拟和实验表明，存在一个最佳正则化范围，通过平衡线性性能和非线性失真可优化对比度。
