A simple model of the sound insulation of gypsum board on resilient supports

A simple model is developed to explain the effects of adding resilient channels to a rigid double leaf wall or floor system. The surface layers mounted on resilient channels are treated as a vibration isolator with a fundamental resonance frequency determined by the combination of the stiffness of the resilient channels and the stiffness of the air cavity along with the masses of the surface layers. The effective stiffness of various common forms of resilient channels is found to be approximately equivalent to that of a 160 mm air cavity. The damping of constructions including resilient channels and cavities with sound absorbing material is found to vary with cavity depth. While the model is useful to optimise the low frequency performance of double leaf constructions with resilient channels, it also demonstrates that the practical range of improvements is limited.