Digital Multi-Zone Audio System

What is this patent about?

’102 is related to the field of multi-zone audio systems, specifically those that distribute digital audio streams from multiple network-connected devices to different speaker zones within a building. Existing systems often involve complex wiring, significant power consumption, and analog signal processing, leading to potential signal degradation and installation challenges. The invention aims to simplify installation, improve audio quality by maintaining a digital signal path, and reduce energy consumption.

The underlying idea behind ’102 is to create a centralized device that receives multiple digital audio streams over a network, buffers these streams to account for network delays, and then routes each stream to a selected zone's digital amplifier. This is achieved using an embedded computer for network connectivity and stream management, and an audio stream manager (implemented using an FPGA or RTOS) to handle buffering, routing, and digital signal processing before sending the audio to digital amplifiers connected to speakers in each zone.

The claims of ’102 focus on a digital multi-zone audio system comprising an embedded computing device and an audio stream manager. The embedded computing device receives digital audio streams from network-connected devices and presents a user interface listing available zones. The audio stream manager then receives these streams and a user's selection of a specific stream and target zone(s), and transmits the selected stream to the appropriate digital amplifier connected to the speaker(s) in the chosen zone(s).

In practice, the system allows users to select audio sources from devices like smartphones or computers and direct them to specific zones within a building. The embedded computer, such as a Raspberry Pi, handles network communication and stream parsing, while the audio stream manager, often an FPGA, buffers the audio to ensure smooth playback despite network irregularities. The FPGA then acts as a digital multiplexer, routing the selected audio stream to the appropriate digital amplifier for each zone.

A key differentiation from prior approaches lies in the end-to-end digital signal path and the centralized management of multiple audio streams. Instead of relying on analog signal processing or distributed amplifiers with individual power supplies and network interfaces, ’102 uses a central device to buffer and route digital audio, minimizing signal degradation and simplifying installation. The use of an FPGA for audio stream management allows for precise clocking and low-latency routing, resulting in high-quality audio and efficient resource utilization. The system also incorporates features for remote administration , volume limiting, and diagnostic capabilities to address installation errors.