Reverberation Room Sound System Loudspeaker Selection 2005-01-2442
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.
Data will be presented to show the difference of on-axial response in an anechoic environment versus a space average level in a reverberation room. This paper will then explore methods for predicting the resultant sound level in the reverberation room given the loudspeakers specifications. In addition, traditional approaches to increasing the available signal sound power level produced within the reverberation room will be reviewed and critiqued.