AES 5th International Conference on Automotive Audio

Analysing and simulating loudspeaker systems in vehicles is a complex task. In order to be able to make a statement about the sound characteristics at an early stage of development, various physical disciplines must be coupled together. The simulation starts with electromagnetism and is followed by mechanical modelling, which in turn is linked to the acoustic model via the diaphragm speed. Some audio systems consist of more than 20 loudspeakers that are used simultaneously, each of which is designed for a different frequency range. A rough categorisation is made here into the low, mid and high frequency ranges, whereby each of the ranges presents different difficulties for the simulation.
The focus of this article is on the high frequency range, which places great demands on the acoustic simulation with classical discretisation methods, such as the finite element method (FEM) or the boundary element method (BEM), particularly due to the short wavelengths. In order to obtain the prediction in the entire frequency range up to 20,000 Hz, either accelerated methods, such as the fast multipole BEM, or energetic methods, such as the energy BEM/FEM, must be used. Their feasibility is to be validated using a generic car measurement setup. In addition to the numerical challenge, there are also special demands on the measurement setup in this area, as only small changes in the microphone position can lead to significant differences due to the short wavelengths.

ID:03_Dilba