Numerical method to predict active control efficiency for a double panel separating two rooms

In this paper a numerical investigation to improve low frequency sound transmission performance of double wall systems by means of active noise control is presented. The double wall is placed in a laboratory situation, i.e. between an emission room and a reception room. The control sources are distributed in a plane surface inside the air cavity coupling the two plates. The double wall is excited by an acoustic field generated by a sound source placed in the corner of the emission room. The numerical double wall model is based on finite element method; the acoustic field in the reception room is obtained from an integral method using the receiving room Green’s function. The model allows to investigate the effect of the number of control channels, the thickness of the double panel cavity, the distance between control sources and error microphones, the number of acoustical modes of the air cavity as well as effects of the active control inside the emission room.