A Comparison Between Active and Passive Approaches to the Sound Quality Tuning of a High Performance Vehicle

Sports car sound quality regularly has two conflicting targets, meeting customer's expectations for interior noise and enhancing the driving experience whilst complying with exterior noise legislation. To help with this balancing act acoustics engineers have an ever growing arsenal of tools to choose from. The conventional sound character development approach would typically involve the tuning of existing vehicle systems, primarily the air-intake and exhaust system. Increased flexibility to interior noise sound character tuning has been offered by the development of sound enhancement devices. The number of sound enhancement devices now commercially available has grown significantly in recent years but the systems can be broadly split into two main categories. Passive systems such as intake sound generators that aim to boost the levels of existing noise sources and more recently the advent of electronic sound enhancement through loud speakers and inertia shakers. This paper presents the results of a sound quality tuning exercise conducted on a Bentley Continental GT which compared differing approaches for three attributes; sound quality, ease of implementation and customer perception.