An audio feedback system that iteratively uses a room as a sound filter can be an artistic medium generating fascinating sounds. In this system, the room is not the only component acting as a filter. The sound system component, i.e. the speaker and microphone, also can have a sizeable impact on the sound in each iteration. To make sure the relative influence of the room on the sound is revealed and not masked by the audio system, the author proposes using a common calibration method at the end of each iteration. The mathematical model of the system is used to explain the reasoning behind the use of this method. Following this procedure, the author conducted an experiment that shows sound interaction with the room over time being captured in the artwork.