Abstract: An acoustic testing system includes at least four control microphones, at least four acoustic transducers, an acoustic enclosure with pre-determined reverberant characteristics which contains the at least four control microphones and the at least four acoustic transducers, a control system configured to produce a predetermined acoustic field as measured by the at least one control microphone. A unit under test is also disposed within the acoustic enclosure. Using an acoustic enclosure with pre-determined reverberant characteristics results of the increased proportion of reflected sounds in the area proximate to the unit under test such that less power is required to achieve a given acoustic test level than in a purely direct field acoustic test.

Abstract: A direct field acoustic testing system includes at least two acoustical transducer groups and a signal modifier for introducing separately controllable time delays or phase shifts for each acoustical transducer group so as to provide an acoustic field conforming to a pre-determined specification with reduced deviations due to constructive or destructive interference between the acoustical transducer groups.

Abstract: A direct field acoustic testing system provides an acoustic field having a higher degree of spatial uniformity. The system includes a control microphone, a controller, a combiner, and at least four acoustic transducers. The controller is operatively coupled to the control microphone such that the controller receives at least one input signal from the control microphone and provides at least four separately controllable controller output signals. The combiner combines the at least four separately controllable output signals to form at least four secondary output signals, each composed of combinations of one or more of the at least four separately controllable controller output signals. Each of the at least four transducers is operatively coupled to at least one of the at least four secondary output signals such that the output of the transducer varies in response to changes in at least two of the at least four separately controllable controller output signals.