Pb(Sb0.5Nb0.5)x(Zr0.51Ti0.49)1-xO3 (abbreviation: PSN-PZT) ceramics were synthesized, using conventional bulk ceramic processing technology, with various PSN doping contents. The maximum density of PSN-PZT was 97% of the theoretical density in the samples sintered at 1,250℃. The maximum values of the piezoelectric properties achieved using the conventional processes were: kp of 0.625, d33 of 531 pC/N, and g33 of 33 mV·m/N. Finally, we fabricated a piezo-speaker with the optimized PSN-PZT ceramics. The SPL of the speaker was measured at a distance of 1 m, with a driving voltage of 40 Vrms in the frequency range of ~300 Hz to 9 kHz. The measured SPLmax was at a very high level (95 dB), which was superior in quality in comparison with those of other commercial products.