Consider a standard standing wave thermoacoustic setup with a stack at 1/4th from the end of one tube( the stack is a concentric type with a certain length. Note that I am not using a heated gauze directly) The stack is made concentric. One end is heated, the other is cooled. Sound is emitted. Now I have the following question on it's mechanism: Will there be only one, big sound wave be generated in the tube, or will there be a number of smaller individual sound waves, each sound wave coming from one point on the roll, since there is no continuity of material the ends of the stack(concentric rolls).