A comparison of the underwater acoustic performance of single crystal vs. piezoelectric ceramic based cymbal projectors

The underwater acoustic performance of three same-design ´cymbal´ based electro-acoustic projectors are compared. Two of these projectors contain PMN-PT single crystal piezoelectric as the active material while the third utilizes conventional PZT-5H piezoelectric ceramic. The units containing the single crystal material show an improvement in the acoustic source level anywhere from 3 to 15 dB over the frequency band 1-25 kHz. The higher source level is a consequence of the higher drive voltage capability of the single crystal materials. Under appropriate drive conditions, a single crystal cymbal-based projector that is 64 mm thick with an acoustic aperture of 101 mm /spl times/ 101 mm can generate an acoustic source level of at least 175 dB (re: 1 /spl mu/Pa @ 1 m) from /spl sim/3 kHz to > 25 kHz.