A Study on the Subwoofer Rattle Noise Analysis and System Target Setting

Rattling noise from electrical sound systems is becoming one of the prominent issues for automakers as it directly affects the perception of customers about vehicle quality. Recently, quality sound system is prerequisite for automotive passenger vehicles. And, in the whole systems subwoofer forms dominant part of sound output. However, subwoofer rattle noise problems sometimes occur in small and midsize Sports Utility Vehicles (SUV). Mainly rattle is noise resulting from physical contact of two parts due to vibrations when relative displacement is bigger than gap of two parts, it occurred certain frequency (Between F1~F2), which is main excitation range of subwoofer. In this study, we analyze the subwoofer structural vibration analysis for five sample vehicles based on the test and correlation. However, the present subwoofer system model has limitation in determining the level of this rattle noise. Therefore, this paper discusses how to correlate subwoofer model, frequency, identification of rattle problems and improvements based on the model correlation. In addition, after the measurement and calculation for the subwoofer excitation force, the actual load condition has been applied in the model. As a result, the correlation level of the subwoofer system was significantly enhanced compared to the initial model, and it was helpful in identifying rattle problem. Also, the reasonable system target to avoid subwoofer rattle noise has been considered. In future, this study can be used to guide design at early stages of vehicle development to avoid rattle problems and overall Computer Aided Engineering (CAE) process.