Sound insulation of double panels - Comparison of existing prediction models

Numerous qualitative comparisons between existing prediction models for the sound insulation of double panels have been presented in the literature but quantitative comparison between models is still lacking. It is important to have impartial evidence of the applicability and accuracy of the prediction models before any of them can be applied for real double wall structures. The aim of this study was to present a qualitative and quantitative comparison of the existing double wall prediction models. Seventeen models were implemented. Quantitative comparison between models was made in four categories: without studs and cavity absorbent, without studs and with absorbent, rigid Studs with absorbent, and flexible studs with absorbent. The quantitative comparison of the models was made against measurement data containing altogether 52 laboratory tests for double walls. The average prediction errors for individual frequencies were as high as 20 dB (R-w: 15 dB) for most of the models, while it was less than 10 dB (R-w: 5 dB) for the best models. None of the models was sufficiently accurate in all four categories. There is an obvious need to develop a new model, which can be reliably applied to arbitrary double and multilayer walls. In the present situation, the most accurate model should be selected according to the type of the double wall.