public address equipment
71Tweeter — A tweeter is a loudspeaker designed to produce high frequencies, typically from around 2,000 hertz to 20,000 hertz (20,000 Hz, generally considered to be the upper limit of the human hearing). A few tweeters can manage response up to an octave or …
72Balanced audio — is a method of interconnecting audio equipment using impedance balanced lines. This type of connection is very important in sound recording and production because it allows for the use of long cables while reducing susceptibility to external… …
73Instrument amplifier — This page is about amplifiers for musical instruments. See also instrumentation amplifier, a type of operational amplifier. An instrument amplifier is an electronic amplifier that converts the often barely audible or purely electronic signal from …
74Race caller — A race caller is a public address announcer or sportscaster who describes the progress of a race, either for on track or radio and TV fans. They are most prominent in horse racing, auto racing and track and field events.Among the jobs of a race… …
75Electronic amplifier — A practical amplifier circuit An electronic amplifier is a device for increasing the power of a signal. It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. In… …
76Antenna (radio) — Whip antenna on car …
77Railways in Melbourne — Melbourne rail network  City Loop  Caulfield group  Frankston line  Pakenham line  Sandringham line  Cranbourne line …
78Stromberg-Carlson — This article is about Stromberg Carlson, the American telephone equipment manufacturing company. For the phone phreak with a similar name, see Strom Carlson. Stromberg Carlson was a telecommunications equipment manufacturing company formed in… …
79Civil defense siren — Federal Signal Thunderbolt 1003 Civil Defense siren. A civil defense siren (also referred to as an air raid siren, tornado siren, tsunami siren, fire siren/whistle, flood siren, weather siren, time/curfew siren, or other outdoor warning siren) is …
80Siemens — For other uses, see Siemens (disambiguation). Siemens AG Type Aktiengesellschaft Traded as FWB:  …
