A stratified biphase structure can have many mechanical resonance modes due to the existence of several length scales in the system. The resonance effect is greatly enhanced if there are periodic synchronized multiple driving sources in the structure. For example, a single beam or a linear array composite transducers used in medical ultrasonic imaging. Such resonance behavior can be studied using an extended transfer matrix technique which we name: multisource T‐matrix technique. Using this technique we have studied the effects of randomization in a 2‐2 composite. It is found that for dispersing the pitch resonance the randomization of ceramic spacing is more effective for low ceramic content, while randomization of ceramic width is more effective for high ceramic content. ©1995 American Institute of Physics.