The invention relates to a scalable video coding method for wireless transmission of high definition television signals. A soundboard according to the invention is constructed as a composite fiber sandwich of a core plate and fiber coating. An adjustable body strap attachment is secured through the frame in non-fixed relationship within a hollow portion. At least an inner cavity of the bladder is provided for the reception of a fluid medium. An analog to digital conversion stage may be shared by the time-multiplexing of the video signals.