| The Holy Grail of distributed audio; unlimited zones and | | | | CAT-5. However, the efficiencies gained by an |
| unlimited sources, cost effectively. That milestone will | | | | integrated speaker / amplifier design would mitigate this |
| be achieved, and soon, through the combination of | | | | concern to some degree. This type of system is |
| digital amplification and IP based distribution systems. | | | | sufficient for background music applications in many |
| There are systems available today that use one or | | | | residential environments. |
| both of these technologies, such as Oxmoor's Zon | | | | Higher power systems can use the existing speaker |
| system and Netlinks' Netstreams product line. The | | | | wire, in the case of a conventionally wired system, to |
| trend will only continue to grow. | | | | carry power. It can / does use the existing control |
| The beauty of this approach is that digital music is | | | | cable, since many systems have been wired with |
| data, and, as such, can be distributed easily via an | | | | CAT-5 to the volume control location, for the data. |
| Ethernet network. The traditional concept of zones | | | | The bandwidth of a traditional 10/100 network allow, for |
| virtually disappears, as each amplifier on the network | | | | all practical purposes, an unlimited number of zones |
| gets a unique IP address, enabling an audio stream to | | | | and sources in a residential environment. Partly |
| be routed to it. When combined with a digital music | | | | because of this, Audio Over Ethernet has been used |
| server, the number of zones is limited only by the ability | | | | successfully in the commercial audio and sound |
| of the server to serve independent audio streams. | | | | reinforcement world for a number of years now. |
| The advent of cost effective digital amplification, | | | | Cobranet, from Cirrus Logic is the most popular |
| produced by companies such as D2 Audio and Flying | | | | commercial AOE system used today. Another popular |
| Mole, allows a small, highly efficient audio amplifier to be | | | | system is available from Digigram. These systems |
| located close to the speakers, either in the room or | | | | both use the MAC layer of Ethernet and are not |
| mounted in an electrical box. The logical evolution of | | | | actually using IP for transmission. |
| this approach is to collocate amplifier with the speaker, | | | | For both residential and commercial applications |
| creating an active speaker. Additional benefits are | | | | another primary advantage of using Ethernet is the |
| realized by incorporating the speaker as part of the | | | | ability to use the medium for transporting both audio |
| circuit. This enables the designer to engineer the | | | | and control signals down the same wire. This |
| speaker and amplifier circuits for optimum | | | | increases flexibility and reduces cost for both |
| performance as a system. | | | | installation and material. |
| Low powered designs of this nature could take | | | | As was true in the commercial world, the distribution of |
| advantage of power over Ethernet (POE), simplifying | | | | audio (and soon, video) and control via Ethernet will |
| system wiring by allowing a single CAT-5 cable to be | | | | continue to proliferate in residential distributed audio |
| run from the router to the speaker. This would not | | | | applications. The combination of flexibility, cost |
| supply a large amount of power (about 15 watts) due | | | | effectiveness and capability are to attractive to be |
| to the constraints of the 24ga conductors used in | | | | ignored. |