Public address systems are often used for background music, for example in shopping centers, hotels and restaurants. In the most simple application, background music can be done with a CD player. In addition, a radio tuner is also often used. Nowadays the use of a so-called internet radio increases.
It is allowed to connect external signal sources, such as background music, to evacuation systems. This can be easily accomplished. The places where there should and should not be played music have to be sufficient inventoried. Especially during the construction the zones should be projected where there is and is no music presented. Of course it is not a good idea to display background music in a hotel room!
‘Caution! Most installations cannot determine whether or not music can be displayed on standard speaker level’
These are complex systems, ergo local switching in a voice alarm system is out of the question and also not allowed.
However, there are developments in the market which make it possible to display background music or other signal sources on speaker level. This should not affect the safety functions and will always need to be discussed with a testing institute.
A good example of this situation is the use of the AB speaker. This is a speaker with two connections, a connection A and a connection B. The connection A is intended for the evacuation signal and the other connection for the external signal sources. A signal on the A connection overrules the B connection.
In fact, these are two speakers in one housing. For example, it is possible for a hotel to use an AB speaker in the hall and in the rooms only a standard evacuation speaker. This is absolutely useful, because in the past there always had to be applied two speakers in those places where background music and voice alarm evacuation were needed.
The speakers for the voice alarm evacuation do not need to be connected to a separate zone. In the hall the B speaker is connected by an extra cable to the network. Generally one uses therefore an extra pair in the wiring of the evacuation system for connecting the B speaker. The total costs for such a project do not significantly increase.
The B speakers will be powered by a separate amplifier. This does not have to be an evacuation amplifier, so in most cases it can be much cheaper.
‘This is a smart application which is used more often’
It pays off to put some time and energy in the formulation of the requirements of a type A evacuation system. Often a small additional investment in the system has a lot more useful features and thus enjoyment of such an installation.