Reciprocity validation of a low frequency volume velocity source inside various enclosures

Volume velocity sources are often used in enclosures to excite a frame and measure responses at locations where other types of force inputs may not be possible. Reciprocal methods are then used to identify the effects of the excited structure on a listener's ear within the enclosure. These methods depend on the volume velocity source acting as a monopole point source. Here, reciprocity tests using a low frequency volume velocity source are conducted in various enclosures to assess the validity of the monopole point source assumption. Results in the free field and auto-body enclosures generally support the assumption. However, results in smaller enclosures and partial enclosures such as HVAC cabinets are more nuanced.