A civil defense siren is a siren used to provide an emergency population warning to the general population of approaching danger. Initially designed to warn city dwellers of air raids during World War II, they were later used to warn of nuclear attack and natural disasters, such as tornadoes. The generalized nature of sirens led to many of them being replaced with more specific warnings, such as the broadcast-based Emergency Alert System and the Cell Broadcast-based Wireless Emergency Alerts and EU-Alert mobile technologies.
A guitar amplifier is an electronic device or system that strengthens the electrical signal from a pickup on an electric guitar, bass guitar, or acoustic guitar so that it can produce sound through one or more loudspeakers, which are typically housed in a wooden cabinet. A guitar amplifier may be a standalone wood or metal cabinet that contains only the power amplifier circuits, requiring the use of a separate speaker cabinet–or it may be a combo amplifier, which contains both the amplifier and one or more speakers in a wooden cabinet. There is a wide range of sizes and power ratings for guitar amplifiers, from small, lightweight practice amplifiers with a single 6-inch speaker and a 10-watt amp to heavy combo amps with four 10-inch or four 12-inch speakers and a 100-watt amplifier, which are loud enough to use in a nightclub or bar performance.
A public address system is an electronic system comprising microphones, amplifiers, loudspeakers, and related equipment. It increases the apparent volume (loudness) of a human voice, musical instrument, or other acoustic sound source or recorded sound or music. PA systems are used in any public venue that requires that an announcer, performer, etc. be sufficiently audible at a distance or over a large area. Typical applications include sports stadiums, public transportation vehicles and facilities, and live or recorded music venues and events. A PA system may include multiple microphones or other sound sources, a mixing console to combine and modify multiple sources, and multiple amplifiers and loudspeakers for louder volume or wider distribution.
A siren is a loud noise-making device. There are two general types: mechanical and electronic. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks. Sirens are used on emergency service vehicles such as ambulances, police cars, and fire engines.
An air horn is a pneumatic device designed to create an extremely loud noise for signaling purposes. It usually consists of a source which produces compressed air, which passes into a horn through a reed or diaphragm. The stream of air causes the reed or diaphragm to vibrate, creating sound waves, then the horn amplifies the sound making it louder. Air horns are widely employed as vehicle horns, installed on large buses, semi-trailer trucks, fire trucks, trains, and some ambulances as a warning device, and on ships as a signaling device.
A steam whistle is a device used to produce sound in the form of a whistle using live steam, which creates, projects, and amplifies its sound by acting as a vibrating system.
A bass amplifier is a musical instrument electronic device that uses electrical power to make lower-pitched instruments such as the bass guitar or double bass loud enough to be heard by the performers and audience. Bass amps typically consist of a preamplifier, tone controls, a power amplifier and one or more loudspeakers ("drivers") in a cabinet.
The Fender Bassman is a series of bass amplifiers introduced by Fender during 1952. Initially intended to amplify bass guitars, musicians used the 5B6 Bassman to amplify other instruments, including electric guitars, harmonicas, and pedal steel guitars. Besides being a popular and important amplifier in its own right, the Bassman also became the foundation on which Marshall and other companies built their high-gain tube amplifiers.
Federal Signal Modulators are electronic warning devices produced by Federal Signal Corporation that are used to alert the public about tornadoes, severe weather, earthquakes, fires, lahars, tsunamis, or any other disaster. They are identified mostly by their distinctive stacked "flying saucer" design. The Modulator II is sold based on the more compact chassis of the siren compared to the original Modulators.
The Chrysler Air Raid Siren is an outdoor warning siren produced during the Cold War era that has an output of 138 dB(C) at 100 feet.
The Whelen Engineering Company is an American corporation that designs and manufactures audio and visual warning equipment for automotive, aviation, and mass notification industries worldwide. Founded in a Deep River, Connecticut garage in 1952, Whelen has become a provider of warning lights, white illumination lighting, sirens, and controllers. Whelen products are designed, manufactured, and assembled in two facilities in Chester, Connecticut and Charlestown, New Hampshire.
The Mount Rainier Volcano Lahar Warning System consists of two separate components, operating in tandem: Acoustic Flow Monitors (AFM) and the All Hazard Alert Broadcast (AHAB) sirens. The AFM system was developed by the United States Geological Survey (USGS) in 1998 and is now maintained by Pierce County Emergency Management. The purpose of the warning system is to assist in the evacuation of residents in the river valleys around Mount Rainier, a volcano in Washington, in the event of a lahar. Pierce County works in partnership with the USGS, the Pacific Northwest Seismic Network (PNSN), Washington Military Department's Emergency Management Division, and South Sound 9-1-1 to monitor and operate the system.
American Signal Corporation (ASC) is an outdoor warning siren and mass notification company in the United States. ASC was founded in 1873 as Biersach and Niedermeyer (B&N). After performing poorly, the company reformed as Alerting Communicators of America (ACA) in 1968, and expanded the line of warning systems they produced. In 1992, ACA went bankrupt and was bought and reformed as the American Signal Corporation.
In civil defense sirens, the ATI High-Power Speaker Station (HPSS) is an electronic outdoor warning siren manufactured by Acoustic Technology, Inc (ATI) that is used to alert citizens of air raids, and natural disasters.
The Public Warning System (PWS) is a network of civil defense sirens installed by the Singapore Civil Defence Force on over 2,000 strategic points in Singapore to warn Singaporeans of impending dangers, air raids and atomic bomb blasts. Thus far, the siren network has only been used for occasional public awareness drills, monthly noon chimes and for commemorating the island's Total Defence (February 15) and Civil Defence Days (September 15). It was also used to mark a minute's silence nationwide for the passing of former prime minister Lee Kuan Yew on the evening of 23 March 2015 and on 1 and 9 August 2020 to mark the first National Day at home.
The Federal Signal Model 2 is an omnidirectional outdoor warning siren produced by Federal Signal Corporation.
The ACA Cyclone is an electro-mechanical, omnidirectional, dual-tone outdoor warning siren produced from 1968 to 2007 by Alerting Communicators of America (ACA). Originally intended for civil defense purposes, early versions of the Cyclone are rated at 120dB from 100ft, and later models are rated at 125dB.
The Federal Signal 3T22 and 2T22 are dual-tone, mechanical outdoor warning sirens made by Federal Signal Corporation from 1952 through the early 1990s. Both have a very recognizable design, with a ten-port rotor (chopper) on the bottom with ten cones (horns) and a 12-port one on top with twelve cones.
Canadian Line Materials LTD. (CLM) was a Canadian siren manufacturing company which built civil defense sirens. These sirens were built and installed all over Canada to warn residents and military about incoming nuclear attacks from the USSR during the Cold War.
The Thunderbolt is a mechanical outdoor warning siren that was manufactured by Federal Signal Corporation from 1951 until its production ended in 1991. It is a unidirectional, rotating siren with a large square-shaped horn, and can come in various colors, usually yellow, by request.
