Wave field synthesis for spatially individual sound using dielectric elastomer loudspeakers 

Team leader: Michael Gareis (Technical University Of Berlin)
Description:
"Wave field synthesis (WFS) is a technology for creating arbitrary wave fields by using multichannel audio systems. To fully satisfy the theory, an infinite number of channels over a closed surface of the space is required. To put WFS into practice, the theory is discretized to a finite number of loudspeakers on a finite-sized array. Yet, a large number of closely spaced loudspeakers is required. High cost, size, and weight of conventional systems prevent widespread application, and WFS remains a niche technology.
The Buckling Dielectric Elastomer Transducer (BDET) loudspeaker concept promises a solution to these technical challenges. The loudspeaker consists only of a 3D printed frame and a DE-membrane that buckles up under voltage-induced area extension. An AC voltage, superimposed on a DC voltage, causes vibration and sound radiation. No mechanical bias by magnets, springs, or air-pressure is required, resulting in an extremely lightweight and thin setup.
A WFS system including loudspeakers, electronics, and software has been developed to demonstrate the structural advantages of the BDET. 480 loudspeakers are built and installed into an array of 48 individual channels. A HV amplifier supplies both the DC offset and the audio voltage. Different scenarios have been implemented in the software, to demonstrate WFS. The WFS is not only suitable for sound reinforcement in rooms, but also in vehicles where different individual audio content is required in a confined space."