Measurement of the viscoelastic constants of the cellulose used for a loudspeaker membrane and their effect upon the electro-acoustic parameters of the loudspeaker

The concept of a complex Young's modulus, characterizing the properties of materials with internal loss, has been introduced. The methodology of the measurement of Young's modulus and a detailed description of the method of measuring this quantity for cellulose used for a loudspeaker membrane is given. Results of measurements of the viscoelastic parameters of six kinds of cellulose are presented, and a marked influence of the absolute value of the complex Young's modulus for cellulose on the upper frequency limit of a loud¬speaker with a membrane made of this cellulose is shown. Subjective investi-gations of loudspeakers have confirmed this conclusion.