An acoustical stack for use within an ultrasound transducer that has a center frequency has a poled piezoelectric material layer and at least one impedance matching layer. The poled piezoelectric material layer has top and bottom sides and is formed of poled piezoelectric material that has a first acoustic impedance. The poled piezoelectric material layer has a first thickness and the acoustical stack has an output electrical impedance based on the first thickness. The impedance matching layers are configured to be attached to the top and bottom sides of the poled piezoelectric material layer and have second or third thicknesses. The impedance matching layers are formed of one or more materials that have an acoustic impedance substantially similar to the first acoustic impedance. The poled piezoelectric layer and impedance matching layers form an acoustic resonance thickness. The center frequency of the transducer is based on the acoustic resonance thickness.