Frequently asked questions

What are the application areas of our sirens?

  • Fire brigade warning alarms
  • Civil defense
  • Civil protection
  • Flood warnings
  • Tsunami warnings
  • Industrial plants (warning and information for employees, protection of the neighbors in case of disasters)
  • Various special applications

What is the siren’s size that should I choose for my application?

It depends on the following factors:

  • Space of the area which has to be covered by the siren signals (topography)
  • Structure of the area which has to be covered by the siren signal (open terrain, lowland, mountain, rural area, urban area, industrial areas)
  • Population density and buildings’ heights
  • Surrounding terrain  (high trees, tree avenues, forests)
  • Ambient noise level (e.g.: road, rail, traffic, industrial and commercial noise)
  • Climate (temperature, humidity, wind strength, precipitation)

Simply, send us the planned location for your siren and we will perform a visual sound propagation prognosis for you. We will also assist you to choose the right location for your sirens.

Which acoustic signals can our electronic sirens propagate?

Digital amplifiers make it possible to offer the following acoustic signal options with our sirens:

  • Warning signals with variable tones
  • Pre-recorded voice messages
  • Live announced messages by microphone (live PA)

We will gladly help you in selecting and recording suitable signals and voice messages.

How do our electronic sirens spread the sound?

The circular shape of a conventional E57 motor siren allows the sound to propagate 360 degrees in horizontal direction. The horns of our electronic sirens may not give this impression to the observer immediately. However, the so-called Omni-directional propagation of the sound wave is based on a "Huygens principle". This physical principle states that the sound is diffracted at a slit. Such a split is also found in our siren horns. By this diffraction a circular sound wave with Omni-directional characteristic finally arises. So, 360 degree sound propagation is also possible with ECN-D or ECI electronic sirens.

What is the difference between the mechanical and the electronic sirens?

Mechanical sirens (motor sirens) are made up of a rotor and a stator. The rotor is driven by closing a relay in the power supply. The rotation creates an air streaming, which is cut off through the openings in the stator. That finally creates a howling noise. Alternating opening and closing of the relay influences the rotational speed of the rotor and thus causes the siren to roar and fade away.

Electronic sirens emit signals in digital form via loudspeakers (drivers) and electronic amplifiers. Thus the howling sounds of a mechanical siren (motor siren) can easily be simulated. The advantages of the electronic siren are mainly their high efficiency with much lower power consumption. Most important, as the electronic sirens are equipped with batteries, they can be operated without mains voltage in case of alarming.

What are the power sources of our electronic sirens?

Our sirens are operated by two integrated 12 volt batteries, which are supplied by a charge controller with single-phase alternating current of 230 V or 110 V +/- 10%. Thus the functionality of the sirens is ensured even in case of a temporary power failure.

It is also possible to install solar cells as an additional voltage source for battery charging.

What is the price of our electronic sirens?

It is our philosophy to offer each client a customized solution that fully meets his requirements. That’s why we do not have standard products with a corresponding price list. We want to develop a specific system for each customer, and we are always meticulously pursuing the goal of maintaining a fair balance between costs and benefits.

Where can you buy our electronic sirens?

Please send us an inquiry with your special request by e-mail to Depending on your region, if you are in Germany we will forward these directly to our respective branch offices, so that the responsible sales person can get in touch with you directly.

Internationally, we have several years of cooperation with fixed sales partners in numerous countries all over the world. If your inquiry concerns a project outside Germany, we will get back to you as soon as possible to connect you with the respective contact person of the country concerned.

Which communication media are used to trigger and monitor our electronic sirens?

All current private and commercial transmission media:

Radio Communications:

  • Analog- and digital radio (DMR)
  • Mobile radio
  • Satellite communications

Wired Connections:

  • Leased line
  • Fiber optics
  • Ethernet

In this case, own infrastructures (typically: radio), client-side infrastructures (typically: Ethernet) or provider-based infrastructures (typically: mobile radio) are used individually or in combination (redundancy).

If your communication medium is not listed here, please contact us with your inquiry - as we customize our siren systems for every client, we will certainly find a solution for your specific project.