Study On Sound Quality Of Automobiles With Different Speaker Designs

The thesis on hand evaluates automotive audio systems based on literature research and experiment data evaluations.The aim of this research work is to find relations between the number and arrangement design of loudspeakers inside of a vehicle cabin.The main focus of this work lies in determination of characteristics of interior sound quality of automobiles and the improvement of automotive audio systems.The research is divided into three parts.First,a broad literature review is conducted.General construction concepts of loudspeakers,automotive interior sound field and quality characteristics are described to set the basic knowledge of the research work.A brief characterization of active sound design targets complements the research in addition.Furthermore there are created connections between general interior sound field characteristics of a vehicle and the influence of the sound wave creation of the audio system on the interior sound field perception.Out of this,there are selected specified concrete design criteria of automotive audio systems.The technical differences of automobile audio system designs of vehicle brands and audio system brands are becoming more complex.Therefore the second part gives a current status of automotive audio systems on the market which are implemented by OEMs into their products.A detailed evaluation and analysis of audio system arrangements of well-known brands,such as Bose,HarmanKardon and Burmester,which are cooperating with OEMs,e.g.Nissan,Mazda,Audi,Mercedes and Porsche,is developed.The analysis respects the different vehicle segments and their specific characteristics concerning sound problems.The section finalizes with a structure and explanation of technical differences of today’s built-in audio systems from the compact class up to middle and upper class vehicles as well as SUVs and sports cars.This section is completed by stating trends and development tendencies of automotive audio systems designs and future aims of OEMs.The third part of this work is about performing and evaluating a sound quality experiment with a selected vehicle.Using three types of music genres,defined engine and vehicle states and evaluating deviated sound quality parameters of the recorded noise allows the writer to compare the sound quality of four seating positions.This leads to suggestions in improving the interior sound quality and audio system design of the chosen vehicle.This work is concludes with general suggestions to improve the interior sound quality of a vehicle based on identified effects of the number and position of speakers.