An important development trend of fiber-optic acoustic sensors (FOASs) is application flexibility and universality. However, the existing more mature FOASs are usually only suitable for a single acoustic test field. In the present study, the FOAS based on high quality factor (high-Q) Fabry-Perot etalon (FPE) has been verified to overcome the above shortcoming by taking advantage of the adjustment flexibility of phase modulation spectroscopy. Among them, the effects of different modulation frequencies on the demodulated characteristics of high-Q FPE and the acoustic performance of FOAS based on high-Q FPE are analyzed theoretically and experimentally in detail. The experimental results for the demodulated characteristics of the high-Q FPE at different modulation frequencies are consistent with theoretical analysis. Moreover, the FOAS based on the high-Q FPE achieves wide sensitivity from 2 mV/Pa to 530 mV/Pa and dynamic range from 90 dB to 107 dB under different modulation frequencies. Therefore, the FOAS can be used not only in high sensitivity acoustic test fields such as sleep monitoring, photoacoustic imaging and so on, but also in large dynamic range acoustic test fields such as aeroacoustics, consumer electronics and all that. The progress of FOAS technology will be promoted to a great extent on account of the application flexibility and universality of the proposed FOAS with excellent performance.