A LEAST-SQUARES METHOD FOR EVALUATION OF CHARACTERISTICS OF ACOUSTICAL SOURCES

A multi-load method to determine source characteristics is presented here. The method is simple: only one microphone is used and no second noise source is needed. It is shown that a larger amount of information gained from the system due to more loads avoids stability problems. The validity of the source parameters obtained by the method is compared with the prediction of insertion loss and of the noise production at the output of a known load. Both theoretical predictions and experimental results are compared: the agreement is good. Further explanations are given regarding stability problems occurring in the so-called four-load method. The method gives better results for relatively complex sources (non-constant impedance) than the four-load method, although consuming more time in measurement because of the extra loads.