The diameter of cylindrical transducers employing the radial mode of operation can be extended to permit resonant operation to much lower frequency. Heretofore the techniques for assembly of bars into cylinders have limited the practical physical size because of the dimensions of available ceramic bars. This paper describes an assembly method whereby available barium titanate bars can be oriented to provide cylinder wall thicknesses up to 12 in. A 200‐in. diameter transducer will have an operational depth of 10 000 ft without pressure compensation and will resonate at 160 cycles per sec. This cylinder can supply 2 megawatts of acoustic power, essentially nondirectional. The same construction technique can be employed on units for frequencies up to 2000 cycles per sec. The paper also will indicate the power capability as a function of size, and stacking procedures are shown to realize the optimum source levels. Cylindrical transducers of nickel ferrite employing the conventional technique with permanent magnets installed have measured efficiencies of 69%. Properly associated windings permit a very low electrical impedance. Comparable transducers employing the barrel stave and the brick wall techniques have been evaluated.