Editing Sound reinforcement system (section)

===Input transducers===
[[File:Various-microphones.JPG|thumb|right|200px|Audio engineers use a range of microphones for different live sound applications.]]
[[Image:Polar pattern cardioid.png|thumb|right|170px|[[Cardioid]] mics are widely used in live sound, because their "apple-shaped" pickup pattern rejects sounds from the sides and rear of the mic, making it more resistant to unwanted [[audio feedback|feedback]] "howls".]]

Many types of input [[transducer]]s can be found in a sound reinforcement system, with [[microphone]]s being the most commonly used input device. Microphones can be classified according to their method of transduction, [[polar pattern]] or their functional application. Most microphones used in sound reinforcement are either dynamic or [[Condenser microphone|condenser]] microphones. One type of directional microphone, called ''cardioid'' mics, are widely used in live sound, because they reduce pickup from the side and rear, helping to avoid unwanted feedback from the [[stage monitor system]].

Microphones used for sound reinforcement are positioned and mounted in many ways, including base-weighted upright stands, podium mounts, tie-clips, instrument mounts, and [[Headset (audio)|headset mounts]]. Microphones on stands are also placed in front of [[instrument amplifier]]s to pick up the sound. Headset-mounted and tie-clip-mounted microphones are often used with wireless transmission to allow performers or speakers to move freely. Early adopters of headset mounted microphones technology included country singer [[Garth Brooks]],{{sfn |Eargle|Foreman|2002| p=62}} [[Kate Bush]], and [[Madonna]].<ref>{{cite news| last=Badhorn|first=Philippe|title=Interview in Rolling Stone (France)|publisher=[[Rolling Stone]] |date=February 2006 }}</ref>

Other types of input transducers include [[magnetic pickup]]s used in electric guitars and electric basses, [[contact microphone]]s used on stringed instruments, and pianos and [[phonograph]] pickups (cartridges) used in record players. Electronic instruments such as [[synthesizer]]s can have their output signal routed directly to the mixing console. A [[DI unit]] may be necessary to adapt some of these sources to the inputs of the console.