A conventional

loudspeaker A loudspeaker (commonly referred to as a speaker or, more fully, a speaker system) is a combination of one or more speaker drivers, an enclosure, and electrical connections (possibly including a crossover network). The speaker driver is an ...

is an electromechanical transducer that converts an electrical signal into sound. If locally powered, this can also be termed an

active loudspeaker Powered speakers, also known as self-powered speakers and active speakers, are loudspeakers that have built-in amplifiers. Powered speakers are used in a range of settings, including in sound reinforcement systems (used at live music concerts), bo ...

, meaning it contains an

audio power amplifier An audio power amplifier (or power amp) amplifies low-power electronic audio signals, such as the signal from a radio receiver or an electric guitar pickup, to a level that is high enough for driving loudspeakers or headphones. Audio power a ...

that drives the loudspeaker. A network loudspeaker implies the ability to send audio to such a device from a network connection, usually over an

Ethernet network Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

or the

Internet The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...

. In many cases this type of speaker also contains

digital signal processing Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations. The digital signals processed in this manner are a ...

(DSP) to provide the

audio crossover Audio crossovers are a type of electronic filter circuitry that splits an audio signal into two or more frequency ranges, so that the signals can be sent to loudspeaker drivers that are designed to operate within different frequency ranges. Th ...

and other tonal functions that exist in conventional speakers. Network speakers are also known as IP speakers. In many cases the IP speaker is created from an IP audio endpoint — a device with the requisite network connection and ability to process audio packets, but without the actual physical speaker portion — that provides amplified audio to a conventional

or unamplified audio (i.e. line-out) to an amplified speaker or system.

History

Network audio was first introduced in 1983 by John Detreville and W. David Sincoskie of Bell Labs in the IEEE paper "A Distributed Experimental Communications System". Subsequently, in 1988, Polle T. Zellweger, Douglas B. Terry and Daniel C. Swinehart of Xerox PARC introduced

audio over Ethernet In audio engineering, audio and broadcast engineering, broadcast engineering, Audio networking is the use of a Computer networking, network to distribute real-time digital audio. Audio Networking replaces bulky snake cables or audio-specific insta ...

at the 2nd IEEE Conference in a paper entitled "An Overview of the Etherphone System and its Applications". The very closely related technology (nearly synonymous),

Voice over IP Voice over Internet Protocol (VoIP), also known as IP telephony, is a set of technologies used primarily for voice communication sessions over Internet Protocol (IP) networks, such as the Internet. VoIP enables voice calls to be transmitted as ...

(VoIP), which generally consists at a minimum of a microphone on one end, a speaker on the other end, with a network connecting them; began widespread use in 1998 with PCs, followed shortly after by dedicated hardware (phones with built-in VoIP capabilities). Subsequently, the first

Squeezebox The term squeezebox (also squeeze box, squeeze-box) is a colloquial expression referring to any musical instrument of the general class of hand-held bellows-driven free reed aerophones such as the accordion Accordions (from 19th-centur ...

, using networked audio, was released in 2001 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 audio content played by the processor in an IP speaker is communicated from its source across a

packet-switched data network In telecommunications, packet switching is a method of grouping Data (computing), data into short messages in fixed format, i.e. ''network packet, packets,'' that are transmitted over a digital Telecommunications network, network. Packets consi ...

using

IPv4 Internet Protocol version 4 (IPv4) is the first version of the Internet Protocol (IP) as a standalone specification. It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. ...

and

IPv6 Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communication protocol, communications protocol that provides an identification and location system for computers on networks and routes traffic ...

addressing with a

User Datagram Protocol In computer networking, the User Datagram Protocol (UDP) is one of the core communication protocols of the Internet protocol suite used to send messages (transported as datagrams in Network packet, packets) to other hosts on an Internet Protoco ...

(UDP) or

Real-time Transport Protocol The Real-time Transport Protocol (RTP) is a network protocol for delivering audio and video over IP networks. RTP is used in communication and entertainment systems that involve streaming media, such as telephony, video teleconference applic ...

(RTP). The IP Speaker connects to

Unicast Unicast is data transmission from a single sender (red) to a single receiver (green). Other devices on the network (yellow) do not participate in the communication. In computer networking, unicast is a one-to-one transmission from one point in ...

Multicast In computer networking, multicast is a type of group communication where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one-to-many or many-to-many distribution. Multicast differs from ph ...

addresses to enable the delivery of streamed data from a source on the network, to arrive at a single speaker or many speakers respectively.

References

{{Reflist Loudspeakers Audio network protocols Network appliances

History

Designs

See also

References