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High levels of broadband random noise are generally required for conducting sound transmission loss and sound absorption tests within reverberation rooms. However, the sound system components such as loudspeakers, amplifiers, and other elements are often selected with little consideration of the audio engineering principles that govern device as well as system operation. This paper will explore some of the requirements for reverberation room sound systems starting with the acoustical power spectrum needed to overcome the transmission loss of high performance barrier assemblies, the background noise in the receiving room, the background noise floor of measuring instruments, and air absorption within the reverberation room.

High levels of broadband sound are generally required for sound transmission loss and sound absorption tests conducted within reverberation rooms. However, the sound system components such as loudspeakers are often selected with little consideration or knowledge of the audio engineering principles that govern system operation. This paper will address the selection of a loudspeaker system for producing the required sound level in a reverberation room, starting with the sound level requirements in a test room, and a brief review of the fundamental concepts of loudspeakers, including horn loading and compression drivers, radiation efficiency, directivity, power ratings and limits, thermal compression, crossovers, equalization, and spectral balancing resistors. Loudspeaker manufacturer's specification data, such as 1 watt/meter sensitivity, directivity index Q, and power ratings will then be discussed.

Acoustical laboratories for vehicle testing have specialized requirements which differ from those for most conventional buildings and facilities. As a result, the normal design and building process takes on added dimensions which need to be carefully considered and addressed. This paper presents an overview of the process that starts with conceptualization of the laboratory and ends with the validation and qualification of the laboratory, and includes particular emphasis on the inherent peculiarities. Case studies are provided of several potential perils and pitfalls that may be encountered in the process which can adversely affect the usability of the laboratory as well as the validity and repeatability of test results obtained by that laboratory. The paper concludes with suggested courses of action which will help either to avoid or minimize the compromises that imperil the functional effectiveness of a laboratory.

This paper provides an overview of a custom software developed to obtain measurement data in a self-contained acoustic test facility system used for conducting random incidence sound absorption tests and sound transmission loss tests on small samples in accordance with SAE J2883 and J1400 standards, respectively. Special features have been incorporated in the software for the user to identify anomalies due to extraneous noise intrusion and thereby to obtain good data. The paper discusses the thoughts behind developing user-friendly algorithms and graphical user interfaces (GUI) for the sound generation, control, data acquisition, signal processing, and identifying anomalies.