In previous works we presented a DEA-loudspeaker configuration that is based on multilayer, core-free dielectric elastomer roll-actuators (DERA) which drive loudspeaker membranes by
expanding axially. Extensive modelling with electromechanical networks incorporating the mechanical and acoustic loads allowed a significant improvement of the loudspeaker’s
performance with reduced size and capacitive load. In a new configuration we are able to also utilize the circumferential expansion (radial modes) as direct source of sound radiation,
exposing the actuator directly to the sound field. We designed, realized and tested several configurations of loudspeakers with actuators of different configurations and PDMS materials.
The new loudspeaker design incorporates a balanced behavior of the different structural modes, improving the overall sound radiation, efficiency, reliability and extending the frequency
response. Due to the additional radial radiation at high frequencies a much wider radiation characteristic can be achieved compared to conventional broadband membrane loudspeakers.
The loudspeaker concept presented shows promising properties that even surpass conventional electrodynamic loudspeakers in some areas (efficiency, radiation pattern, weight, cost and
material use).