Abstract: An audio distribution system in one embodiment includes a master device, a powered speaker unit, and an expander device. The master device has an output port for receiving a cable carrying an electrical power signal along with a digital audio signal. The speaker unit includes a first port for receiving the electrical power signal and the digital audio power signal, and a second port for sending the signals. A digital-to-analog converter in the speaker unit converts the digital audio signal to an analog audio signal, and a speaker driver uses the signal to produce sound. The expander device is electrically connectable to the second port of the speaker unit for providing electrical power to one or more further speaker units. In another embodiment, the invention provides a master mixer device and a speaker unit.

Abstract: Embodiments of a speaker assembly and cooperating suspension ring designed to allow installation of the assembly in a horizontal ceiling tile from below are disclosed. The speaker assembly includes a body or housing with a flange at one end. The body has a diameter that allows it to fit through a hole the ceiling tile and the suspension ring. The assembly is further provided with clamps attached to the flange next to the body. In order to bring the flange into contact with the ceiling tile, the assembly must be aligned so that the clamps penetrate cooperating voids in the suspension ring. The assembly is then rotated in a direction depending on the tile thickness and lowered into a position where the clamps engage with projections on the suspension ring so that the suspension ring supports the weight of the assembly.