Network speaker

A Loudspeaker is an electromechanical transducer that converts an electrical signal into sound. If locally powered, this can also be termed an active loudspeaker, meaning it contains an audio amplifier that can drive power to the speaker drivers. An network speaker implies the ability to drive audio to such a device from a network connection, usually an Ethernet network or Internet. In many cases this type of speaker also contains digital signal processing (DSP) to provide the audio crossover and other signal processing to provide frequency division and other tonal functions. Many network speakers contain multiple amplifiers, usually one per speaker driver. Network speakers are also know as IP speakers of IP loudspeakers. In many cases the IP Speaker is created from an IP audio endpoint (a device as described above but without the actual physical speaker portion) that provides amplified audio to a conventional loudspeaker.

History

Network audio was first introduced in 1983 by John Detreville and W. David Sincoskie of Bell Labs in an IEEE paper "A Distributed Experimental Communications System"^[1]. Subsequently in 1988, Polle T. Zellweger, Douglas B. Terry and Daniel C. Swinehart of Xerox PARC introduced audio over Ethernet in Proceedings of the 2nd IEEE Conference, entitled "An Overview of the Etherphone System and its Applications"^[2]. Subsequently in 2001, the first Squeezebox was released using networked audio, and Philips released its IP audio device also in 2001, the FW-i1000. Countless IP audio devices have since proliferated into most major audio markets.

Designs

IP Multicast

IP Unicast

The content played by the processor in an IP speaker is communicated across a packet-switched data network using IPv4 and IPv6 addressing with a User Datagram Protocol (UDP) or Real-time Transport Protocol (RTP). The IP Speaker connects to Multicast or Unicast addresses to enable the delivery of streamed data to arrive at a single speaker of many speakers. IP Speakers use a protocol called Internet Group Management Protocol (IGMP) to join these groups.

See also

• Audio over IP

References

1. ^ John Detreville and W. David Sincoskie, "A Distributed Experimental Communications System", IEEE JOURNAL ON SELECTED AREAS IN COMhfUNlCATIONS, VOL. SAC-1, NO. 6. DECEMBER 1983
2. ^ Polle T. Zellweger, Douglas B. Terry, and Daniel C. Swinehart, "An Overview of the Etherphone System and its Applications", Computer Workstations, 1988., Proceedings of the 2nd IEEE Conference on Issue Date: 7-10 Mar 1988

External links

• IP Paging, IP Speakers and VoIP Paging