Homework Statement
A sheet of porous material is suspended in air at a distance of 1/4 wavelength in front of a rigid wall. For the frequency of interest, the mass of sheet is high enough not to move significantly under the influence of a sound wave. When a constant frequency plane wave is...
Homework Statement
Acoustic tile which is locally reacting, for a frequency of 400 Hz, it has a normal-incidence specific impedance of 1500+i3700 (Kg/m2s). A plane wave in Air of 400 Hz sound with a pressure level of 86 dB in the absence of reflection is incident on the tile at an Angle X. How...