Abstract: A transducer assembly for transmitting broadband sonar beams and receiving broadband sonar returned echoes with a low-cost transducer element mounted into a low-cost acoustic structure. By using a transducer element which is sufficiently thin, broadband can be achieved at a significant cost savings over existing methods and devices. Since the transducer element is sufficiently thin, a large portion of the signal energy is coupled transversely into the acoustic structure, resulting in a heavy acoustic load on the transducer element which in turn results in broadband operation. Broadband operation may be enhanced by at least partially enclosing the sufficiently thin transducer element within an aperture and/or a cap.