Editing Civil defense siren (section)

===Electronic ===
[[File:Alertronic High Powered Voice Siren.JPG|thumb|American Signal AL-8000 in [[O'Fallon, Illinois]], US]]

Electronic sirens consist of an electronic [[tone generator]], a high-power [[amplifier]], and a [[horn loudspeaker]]. Typically, the loudspeaker unit incorporates horn loading, causing them to be similar in appearance to some electromechanical sirens. Many of these loudspeakers incorporate a vertical array of horns to achieve pattern control in the vertical plane. Each cell of the loudspeaker horn is driven by one or more [[compression driver]]s. One type of compression driver for this type of loudspeaker uses two doughnut-shaped permanent magnet slugs to provide [[magnetic flux]]. For siren applications, [[high-fidelity]] sound is a secondary concern to high output, and siren drivers typically produce large amounts of [[Distortion#Audio distortion|distortion]] which would not be tolerable in an audio system where fidelity is important. Most newer (and some older) electronic sirens have the ability to store [[Audio file format|digital audio files]]. These audio files could be custom sounds, or emergency messages.<ref>{{Cite AV media|title=Carnation, WA Analog Whelen WPS-2808 Short wail and voice x2, Dam Failure Siren Test|date=7 November 2021|url=https://www.youtube.com/watch?v=DETlhT22-UA|access-date=2023-09-02|language=en|via=[[YouTube]]}}</ref> Depending on the situation, the stored sound file can broadcast through the siren.<ref>{{Cite AV media|title=This is a tornado warning|date=3 September 2009|url=https://www.youtube.com/watch?v=6gJ9DOzYnqE|access-date=2023-09-02|language=en|via=[[YouTube]]}}</ref> These sirens could also come with a [[Phone connector (audio)|Microphone Jack]] to broadcast live messages via microphone.<ref>{{Cite AV media|title=Modulator 6024B Waialae Beach Park 8-9-2019|date=27 August 2019|url=https://www.youtube.com/watch?v=Ea_29SOIkfc|archive-url=https://ghostarchive.org/varchive/youtube/20211211/Ea_29SOIkfc|archive-date=2021-12-11|url-status=live|language=en|access-date=2021-11-19|via=[[YouTube]]}}{{cbignore}}</ref>

As with [[Electromechanics|electromechanical]] sirens, there are both omnidirectional, directional, and rotating categories. [[Whelen Engineering]] produces sirens which oscillate through 360 degrees, rotating in one direction and then in the other to allow a hard-wired connection between the amplifiers and the siren drivers.<ref>{{Cite AV media|title=Whelen Vortex Slab Rotator Test After Reassembly|date=22 June 2022|url=https://www.youtube.com/watch?v=KhLjL39e_Ag|access-date=2023-09-02|language=en|via=[[YouTube]]}}</ref> These sirens can also be set to rotate any amount from 0 to 360 degrees, allowing sirens to broadcast only in certain directions.{{Citation needed|date=June 2019}}

Electronic sirens may be mechanically rotated to cover a wide area, or may have transducers facing in all directions to make an omnidirectional pattern. A directional siren may be applied where notification is only required for a defined area in one direction.<ref>{{Cite web|title=DSA High-Powered Directional Speaker {{!}} Federal Signal|url=https://www.fedsig.com/product/dsa-high-powered-directional-speaker|access-date=2023-06-09|website=fedsig.com}}</ref>