Don't Throw the Loudspeaker Out with the Bathwater! Two Case Studies Regarding End-of-Line Tests in the Automotive Loudspeaker Industry

Mass production of loudspeakers drivers for the automotive market is subjected to the strong requirements dictated by the implementation of the sector Quality System and is heavily conditioned by the low profit margin of what is seen (and actually is) a commodity as many other components of a vehicle; but, differently from other components, a loudspeaker is a complex system made of parts whose performance depends on many factors, including ambient conditions. For these reasons it is quite difficult to impose tight tolerances on loudspeakers and a fair agreement must be found between suppliers and customers to avoid scraping samples that are fine under any aspect, especially considering that the final judgement mainly stays, although not exclusively, in the ears of the end user. In this work two case studies will be presented to show how tolerances could be fixed reasonably.