Both theoretical and experimental studies have been made to evaluate the acceleration response of square sandwich panels with clamped boundaries under a specific random acoustic excitation. Generalized harmonic analysis was used to compute the response spectrum. The modal frequencies and associated loss factors of the composite used in the analytical estimation of the response were obtained by applying Galerkin's procedure. The effects of modal cross coupling and of the core thickness on the response have been studied. The theoretical estimates of the response are compared with the results from the experiments for certain core thicknesses. © 1981.