Tuning or varying the resonance frequency of a transducer by adding an additional layer of ceramic, called the control ceramic, is a method for designing a wide bandwidth transducer. By loading the control ceramic with an inductive electrical load the resonance frequency of the whole structure is variable or tunable over a wide range of frequency. Two designs of tunable transducer are discussed in this paper; a two‐plate thickness‐driven structure with a fundamental frequency of 240 kHz and a sandwich structure with a fundamental frequency of 30 kHz. Tunable ranges of 1.5 and 1.8 oct are obtained, respectively. It is established that the limit of the tunable range for the two‐plate transducer is between the fundamental harmonic and the second overtone of the whole structure, which are defined with the control ceramic short circuited. For the sandwich transducer the tunable range is between the fundamental harmonic and the first overtone of the whole structure, which are defined when the control ceramic short circuited. An analysis based on the Mason transmission‐line model shows that the fundamental limit of the tunable range is determined by the fundamental resonance frequency and the dynamic coupling coefficient of the drive ceramic and is affected by the presence of any bonds and shims between the ceramics. To obtain a continuously tunable frequency range the position of the drive ceramic must be between the radiating front‐end of the structure and the control ceramic.