Resonant Sonic Crystal is a very high impedance material to attenuate sound with low frequency, which was firstly introduced by the research team led by Professor Ping SHENG. Based on the idea of the traditional Resonant Sonic Crystal, a newly developed and improved of Local Resonant Sonic Material have been invented....[ Read more ]

Resonant Sonic Crystal is a very high impedance material to attenuate sound with low frequency, which was firstly introduced by the research team led by Professor Ping SHENG. Based on the idea of the traditional Resonant Sonic Crystal, a newly developed and improved of Local Resonant Sonic Material have been invented.

This new kind of Local Resonant Sonic Material is also a high impedance material made by plastic grid and different sizes/masses of steel/lead balls confined in silicone rubber medium. It has been introduced because of the more effective and efficient ways to produce the high impedance samples, which can also give very good sound attenuation effects like those traditional Resonant Sonic Crystals.

With the modified measurement technique by using the method of two impedance tubes, the multiple reflection of the impedance of the system among speaker, impedance tube and measuring samples can be eliminated. The complex transmittance of this new type of Local Resonant Sonic Material, including transmission amplitude and phase information, can then be measured from frequencies 120Hz to 1500Hz with high accuracy.