Sound systems: features and applications

Sound is always present in our lives, from home to public spaces where we carry out daily activities: shopping centers, airports, hospitals, plazas, parks, etc. To make the sound reach our ears properly, we use sound systems. Let’s talk about them and their characteristics.

Electroacoustic installations such as public address and voice evacuation systems are used in open and closed spaces to ensure good sound quality and that the messages are intelligible. The objective is to provide the right sound level in any place.

Functions of the sound systems

A sound system allows:

• Strengthen the acoustic signal, particularly in large spaces where direct sound is often insufficient and the sound source needs to be reinforced, or in places where the ambient noise is very high.
• Distribute the sound in different areas, that is, in areas other than the one where the sound source is located.
• Distribute alarm signals and warnings in security facilities that have an advanced public address and voice evacuation system to be able to emit messages and acoustic signals in emergency situations.

Elements of electroacoustic installations

In sound systems, electroacoustic installations are made up of four main elements: the sound source, the audio matrix, the amplifiers and the speakers.

The sound source can be a microphone or a music player. In the case of public address and voice alarm systems, they usually have a player that independently reproduces prerecorded messages in universal audio formats (such as MP3 or WAV). This allows you to store different kinds of messages, from commercial announcements to warning and evacuation messages, and issue them at certain times (manually or on a scheduled basis, directly or remotely) according to the applied technology.

For example, the LDA Audio Tech EN 54 public address and voice alarm systems offer different functionalities according to the needs of each venue. Thanks to its specific SIME software, different areas and contents can be programmed to be distributed at any time, which can also be easily managed remotely.

As for the audio matrix, it controls the signals that arrive from the source before they reach the amplification stage with different functions:

• Audio functions: assign inputs and outputs, dynamic processing, signal equalization, etc.
• Remote control functions: from microphone desks, from computers, through the TCP/IP Ethernet network, programmable input and output contacts, etc.
• Message playback, if it has digital audio storage capacity.

Speakers distribution

Locating the speakers correctly in the space to be played is essential to achieve our goals, that is, to reinforce or properly distribute the audio signal. There are three types of installations depending on how your speakers are placed:

• Centralized or concentrated system, consisting of a single speaker from which all the sound is emitted. We also talk about a concentrated system when there are several speakers located very close together, since they work from the same point for the whole enclosure.
• Zonal system, which is made up of several centralized systems that serve different areas of the installation.
• Distributed system, where the speakers are distributed evenly throughout the installation so that the distance between them is greater than the wavelength of their signals.

When there is a need to sound an open space, centralized or zonal systems are used, with loudspeaker speakers that provide high directivity and sensitivity. In the case of zonal systems, they can be linear (for long and narrow areas) or spatial (for larger and wider surfaces).

If we work in a closed space, we will choose either a concentrated or distributed system. In the first case, we will use acoustic columns aimed to the farthest listener in order to guarantee optimum coverage. Distributed systems involve spreading the speakers throughout the enclosure and providing a uniform sound level.

Do you want more information or advice on distributed public address and voice evacuation systems? Contact our support department and we will be happy to answer your questions.