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The door response to audio excitation contributes to the overall performance of a vehicle audio system on several items: acting as a cabinet, it influences the loudspeaker response, but it also radiates unwanted sound through the inner door panel. Associated design issues are numerous, from the loudspeaker design to door structure and inner panel definition. Modeling then appears as an unavoidable tool to handle the acoustic response of the loudspeaker in its actual surrounding as well as the door inner panel radiation. In the low frequency range (<300 Hz), the loudspeaker is conveniently modelled using the classical Thiele&Small 1 D model. The interaction with the door and the acoustic surroundings requires a more detailed Finite Element modeling considering the acoustic loads on both sides of the loudspeaker membrane and the force at the loudspeaker frame interface with the door structure.

The door response to audio excitation contributes to the overall performance of the audio system on several items. First, acting as a cabinet, it influences the loudspeaker response. Second, due to the door trim inner panel radiation, the radiated power is disturbed. A third effect is the regular occurrence of squeak and rattle, that will not be considered at this stage. Design issues regarding these attributes are numerous, from the loudspeaker design to door structure and trim definition. Modeling then appears as an unavoidable tool to handle the acoustic response of the loudspeaker in its actual surrounding.

The current paper is based on the French research program TESSA (“Transfert des Efforts des Sources Solidiennes Actives”). A specific task within TESSA project consists in the characterization of the measurements variability between several laboratories, of the blocked forces on a water pump of a heat engine. This paper focuses only on the measurements carried out at Vibratec laboratory. Two kinds of measurements have been carried out: direct measurements, using force sensors, which is the target of the inter-laboratory measurements, and an inverse method without force sensor requirements. Reproducibility and repeatability tests have been done in order to quantify the measurement variability within the same laboratory, in preparation for the inter-laboratory disparity analysis.