... art; suitable for high sound quality requiry place studiom, recording room 1 QRD Sound DiffuserReflecting faultsIf a person in a flat ... , hard or harsh, this phenomenon is called frequency dyeing effect. 2.QRD Sound DiffuserQRD Sound Diffuser is a kind of irregular ... *310mmtotal of 14 QRD placed in the central of reverberation room ground,,toatal 10.1sqm