Sound Absorption by Insulating Firebricks

摘要

Drilling non-thru holes on the surface of IFB with high permeability, we can get practical sound absorption at 500～1250Hz. By adopting thru holes and air gap behind IFB, we can get practical sound absorption at 100～500Hz. Both of these absorption may come from resonance and the resonant frequency is controlled by the configuration of holes and air gap.