Speaker
Description
In the automotive domain, flat-panel loudspeakers (FPLs) offer a compelling alternative to conventional electrodynamic transducers due to their reduced form factor and lower moving mass, which facilitate integration into interior trim and improve overall power consumption. However, the acoustic performance of these systems depends on coupled design parameters. The most relevant include surface density, bending stiffness, number, and position of actuators and their actuation principle.This study provides an analysis of piezoelectric actuation within a vehicle cabin, progressing from numerical modeling to a full vehicle audio demonstrator. A multichannel architecture is developed in which piezoelectric actuators are embedded into the headrests, door panels, and an OLED center console. To overcome their low-frequency limitations, full-bandwidth reproduction is achieved using a hybrid setup: a conventional dynamic subwoofer reinforces low frequencies, while piezoelectric elements handle the low-mid to high-frequency range.Furthermore, frequency-dependent directivity is characterized for both the headrest units, critical for personalized audio content, and the OLED center console. The former controls directivity through geometric design. The latter integrates four piezoelectric actuators on the same surface, driven by custom signal processing to exploit structural–acoustic coupling and produce a desired radiation pattern.We present acoustic results for individual components and the complete audio system by analyzing FEM simulations and experimental recordings following procedures recommended by the AES Automotive Audio Committee and complemented by perceptual metrics.This study validates the use of piezoelectric actuators for broadband automotive sound reproduction within a distributed multichannel architecture, highlighting key design trade-offs and limitations.