Page 280 - Advanced Course

KNX ADVANCED COURSE

2.1.2 Extended audio system
An extended audio system can contain several audio sources, an audio mixing device and
several audio outputs, e.g. in music halls, several microphones are used to transfer the
sound of different musical instruments connected to an audio mixing and amplifying
console (analog or digital), to be able to select and adjust the characteristics of each of
them. An amount of speakers can be connected to the output of the audio mixing console
to reproduce the desired sound. Amplifiers may be connected to the microphone and/or to
the speaker lines in order to transmit the signal without any losses.

Figure 2-An extended audio system with digital mixer

2.2 Intercom systems

Defining an intercom system, we could say that it usually consists of a pair of transceiver
devices that may use several media in order to achieve the communication between each
other. On the basis of the type of transceiver devices, one can divide the intercom
systems into two main categories.

2.2.1 'Audio to Audio’ Intercom system
An ‘Audio to Audio’ intercom system usually consists of two or more devices, with
recording and reproducing audio functions embedded, so a user can both speak and hear
another user of the same system.

NOTE: In some cases, this kind of intercom systems uses a call center in order to
connect subscribers, but, in order to save space and time we limit the description only to
peer-to-peer intercom systems.

Figure 3 - An 'Audio to Audio' intercom system
Home and Building Management Systems KNX Association
Multimedia Systems KNX and Multimedia_E1212b.doc 4/15