The invention relates to audio transducers, such as loudspeaker, microphones and the like, and includes improvements in or relating to hinge systems for rotational action audio transducers. The hinge systems of the invention being configured to operatively support a diaphragm in use, and comprising a hinge assembly having one or more hinge joints, wherein each hinge joint comprises a hinge element and a contact member. The contact member comprises a contact surface and the configuration is such that during operation each hinge joint is configured to allow the hinge element to move relative to the associated contact member, while maintaining a substantially consistent physical contact with the contact surface. The hinge assembly biases the hinge element towards the contact surface. Preferably the hinge assembly is configured to apply a biasing force to the hinge element of each joint toward the associated contact surface, compliantly. Various applications and implementations are described and envisaged for the audio transducer embodiments including, for example, personal audio devices such as headphones, earphones and the like.