本文在回热器边界声场调制理论的基础上，考虑了两端换热器和谐振管变径的影响，推导出热声系统（谐振管和回热器）内声场与双声源复声压相关的声场调制关系式。理论和实验分析了双声源复声压对谐振管中的行波比率以及回热器中的声阻抗的调制，并给出通过复声压调制后的系统内声场分布图。对比结果表明该声场调制关系式的适用性，通过双声源复声压的调节，能调制出谐振管及回热器所期望的工作声场。“,”In this paper, on the basis of theoretical analysis for modulating acoustic boundary conditions of a regenerator, the influences of heat exchanges and the diameter variation of resonator are considered and the modulating relations between acoustic field in thermoacoustic system and complex pressure of acoustic drivers are derived. The modulations for the ratio of travelling wave and acoustic impedance by using driving pressures are analyzed theoretically and experimentally, and the distribution of acoustic field along the axial direction is obtained. The comparative result shows that the acoustic modulating relations are feasible, and by complex pressures modulating, the expected acoustic field in resonance tube and regenerator can be obtained.