Experimental Study on a Thickness-Adjustable Absorber for Reverberation Controlling

General adjustable absorbers used in acoustical design is to simply change the size of absorption/reflective surface, this kind of reverberation controlling technique is limited by the weight of absorbers and the interior wall area. Regarded these, a thickness-adjustable absorbers named Multi-film absorbing construction (MFC), was developed for more convenient reverberation controlling. In this study, an reverberation time experiments were designed to research the absorption characteristic of MFC. Test results showed that MFC commonly produces best absorption of low frequencies, and it´s absorption coefficients related to the thickness of water, especially when the thickness changes within 1cm~3cm. Therefore, with participation of water the sound properties of MFC is adjustable with the thickness of water changes, which means more convenient reverberation controlling without change the absorption area.