Measurements of electrical transfer characteristics with soundcards as classroom activity
Stephan Paul, Pascal Dietrich · The Journal of the Acoustical Society of America · 2011
Measurements of transfer functions and impulse responses of different types of systems are an important part in acoustics and should be an integral part in acoustics education. Nevertheless, usually expensive equipment is required to carry out such measurements making it difficult to realize hands-on measurement classes. Contrarily the transfer characteristics of electrical systems can be measured much easier. Electrical systems and acoustics meet in electro-acoustic equipment such as soundcards, which can be found as onboard and external devices and in a wide variety. Input and output of soundcards can be connected by different types of transmission systems that might use different types of electrical circuits adding a variety of transfer characteristics. The inherent transfer characteristics of the given soundcard can be analyzed and compensated before assessing the transfer characteristics of different electrical circuits (black boxes). Thus, the experimental measurement of soundcards together with different black-boxes connected to them can be a good means to perform comprehensive measurements of IR and FRF. Using a MATLAB based measurement software, a measurement set-up has been developed to be used by students in a classroom experience. This contribution discusses the set-up, the results of the different scenarios measured and the feedback of the students.