AES 5th International Conference on Automotive Audio

This workshop discusses the product life cycle of a typical, actively controlled car speaker system from design over pre-production and mass production up to the monitoring and control in the final use inside a car. AVAS (acoustic vehicle alerting systems) are used as an example with respect to special safety and quality requirements. Practical demos during the workshop show typical tasks mandatory for the different phases of product life. Active control comprises the opportunities given by software to support measurements and diagnostics as well as advanced protection and distortion reduction techniques.

The design phase as an early phase balances resources (hardware) and control options (software) to create safe, cost-efficient and sustainable products. This process, known as green speaker design, will be explained shortly. A prototype system is the result of the design phase.

The focus in pre-production is to stress and determine the reliability and robustness of the prototype system for collecting valuable information about limitations and get feedback for possible design improvements. Long term tests under critical conditions, accelerated life testing and the assessment of headroom before failure or destruction are investigated.

In mass production the focus is on fast and reliable reproduction of the prototype including verification at the end-of-line. Particularly for AVAS speaker, leakage testing and comprehensive defect detection in minimal time is key.

Safety requires an early detection of failures in the final use after delivery to customer. Controlled car speakers are permanently monitored and allow a detailed analysis of aging symptoms, excessive distortion, providing indications for potentially failures of the system. Actions can be taken to inform the end-user, the manufacturer and the workshop. The two latter may receive diagnostics information about the time-based variance of the product to efficiently repair the problem and to improve the product quality for next generation products.