Measurement of the viscoelastic constants of the cellulose used for a loudspeaker membrane and their effect upon the electro-acoustic parameters of the loudspeaker
Abstract
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 loudspeaker with a membrane made of this cellulose is shown. Subjective investigations of loudspeakers have confirmed this conclusion.References
[1] D. R. BLAND, The theory of linear viscoelasticity, Pergamon Press, Oxford, London, New York, Paris 1960.
[2] D. R. BLAND, E. H. LEE, Calculation of complex modulus of linear viscoelastic materials from vibrating reed measurements, Journal of Applied Physics, 26, 12, 1497-1503 (1955).
[3] A. DOBRUCKI, Cz. A. ROSZKOWSKI, Measurement of the Young’s complex modulus of cellulose used for loudspeaker membranes, Proceedings of 23rd Open Seminar on Acoustics, Wisła 1976, p. 179.
[4] Cz. A. ROSZKOWSKI, The influence of the material used for loudspeaker membrane upon the acoustic properties of the loudspeaker. Dissertation. Institute of Telecommunication and Acoustics, Wrocław 1976, p. 16.
[5] Z. ŻYSZKOWSKI, A. DOBRUCKI, C. SZMAL, Studies on the relation between the synthetic index of quality and acoustic (auditory) measurements. Report No. 128/R-060/76, Institute of Telecommunication and Acoustics, Wrocław Technical University, Wrocław 1976, p. 52.
[2] D. R. BLAND, E. H. LEE, Calculation of complex modulus of linear viscoelastic materials from vibrating reed measurements, Journal of Applied Physics, 26, 12, 1497-1503 (1955).
[3] A. DOBRUCKI, Cz. A. ROSZKOWSKI, Measurement of the Young’s complex modulus of cellulose used for loudspeaker membranes, Proceedings of 23rd Open Seminar on Acoustics, Wisła 1976, p. 179.
[4] Cz. A. ROSZKOWSKI, The influence of the material used for loudspeaker membrane upon the acoustic properties of the loudspeaker. Dissertation. Institute of Telecommunication and Acoustics, Wrocław 1976, p. 16.
[5] Z. ŻYSZKOWSKI, A. DOBRUCKI, C. SZMAL, Studies on the relation between the synthetic index of quality and acoustic (auditory) measurements. Report No. 128/R-060/76, Institute of Telecommunication and Acoustics, Wrocław Technical University, Wrocław 1976, p. 52.
