The dependence of sound radiation on position of acoustic source in an enclosure

In some applications, acoustic sources may be confined to a small enclosure but still radiating sound out-wards through the enclosure. However, the sound power that is radiated from the enclosure may potentially be impacted by the location of the source within the enclosure and the properties of the enclosure. The dependence of source position on sound power radiated from the enclosure was investigated using a small rigid rectangular enclosure with a flexible aluminum panel as one of the sides of the enclosure. An acoustic source was moved to numerous locations in the enclosure and sound power measurements were made using the ISO 3741 standard. Results will be shown to numerically quantify the effect of acoustic source position on radiated sound power. These results are used to develop a calibration curve between the sound radiated by the enclosed source vs. the sound radiated by the source in a free field environment. This curve can be used in the development of an alternative method of determining sound power for a source.