Room modes can significantly impair the quality of sound diffusion, in particular at low-frequencies and in small auditoria. These low-frequency resonances are the most difficult to control as passive sound absorbers are unable to damp them efficiently. In order to suggest appropriate solutions to this problem, a thorough understanding of the room's sound field is required. One important aspect of this knowledge is the information regarding each and every modes of the room (i.e, eigenfrequency and the corresponding damping factor). Several modal identification methods exist (such as Global curve fitting or Vector fitting), each with its pros and cons. This project aims to investigate different methods both in the time and frequency domain to determine a framework to tackle difficult cases such as when two consecutive modes are too close or when the room is no longer lightly damped.
The project will be structured as follows: - bibliographic study on different room modal characterization methods; - Analyzing these methods in details using numerical data from COMSOL - Suggest a framework taking advantages of the pros and cons of these methods
Prerequisite: Electroacoustics / Audio Engineering lectures; Signal processing
Context: Theory (50%), Numerical Simulation (30%), Experimental work (20%)