Abstract: The invention relates to a dual frequency sonar transducer assembly which may be operated at low and/or high frequencies in a sonar array. The assembly comprises a low frequency unit of tonpilz design including a low frequency driver, a low frequency tail mass and a composite head mass, the composite head mass acting as a single low frequency water driving piston and comprising a plurality of high frequency units forming individual high frequency water driving pistons. The high frequency units are also of tonpilz design, with independent drivers, independent head masses, and a common tail mass. The use of a common tail mass simplifies the design without compromising high frequency operation. The design leads to more efficient operation at both frequencies by minimizing the head mass to tail mass ratios.

Abstract: A transducer includes an acoustic radiating member for generating acoustic energy in a transmitting medium and a driver member that is pivotally connected to the radiating member. The driver member is for urging movement of the radiating member, wherein such movement generates the energy. Pivoting of the driver member with respect to the radiating member relieves predetermined stress in the driver member. The radiating member may include, for example, a flat element such as a bar, plate or disk, or an I-shaped element. The driver element may include an electroactive material. The driver element may be connected to the radiating element by support apparatus that is fixedly coupled to the radiating element includes a screw having a predeterminedly contoured end that engages a complimentarily contoured recess connected to the driver element for permitting the pivoting. When the support apparatus includes a screw it may be adjusted for supplying a predetermined force on the driver element.

Abstract: The electroacoustic transducer disclosed is of double mass loaded piezoelectrically driven type particularly adapted to high power sonar array application. For reducing transducer sensitivity to interference and noise of frequencies at and below the transducer moving assembly mounting resonance, without significant impairment of transducer efficiency even at high power levels in the active mode operating frequency bands, the transducer moving assembly mounting resonance is damped by provision of a resistive coupling which in its preferred form comprises a lossy rubber ring compressed between the transducer housing and the inertia mass. Corona suppression means effective at high power levels of operation as described also are disclosed.