Active increase of sound transmission loss of panels,considerations on different modal control approaches

摘要

There are several approaches to increase the sound transmission loss of lightweight panels byactive means. Most often the approach has been to use structural actuators to change thevibration pattern of sound radiating panels. Another approach has been to attenuate the soundradiation of the well radiating vibration modes using dynamic loudspeakers. A third, lesscommon method, is active broadband sound radiation reduction using a large number of smallloudspeakers or a few large surface acoustic panel actuators. A special approach derived heretheoretically is the modified JMC method applied to modal suppression of flexural vibrationfields of sound radiating thin plates. JMC method, originally developed by Jessel, Mangiante andCanévet for Active Noise Control applications, and modified by Uosukainen, utilizes normallyacoustic actuators. Even if the JMC method applied to Active Structural Acoustic Control(ASAC) has never been tested, the theoretical considerations are interesting, and the method cancontribute to the breakthrough in sound transmission loss increase by active means.