Where does this come from, and can I check it?

A microphone picks up a speaker, which feeds the same tone back louder. The figure is taken from Shure, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a music fact?

Yes. It sits on the Music shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

Feedback is a loop that feeds itself

A microphone picks up a speaker, which feeds the same tone back louder When a microphone hears a speaker and that signal returns through the amplifier at a level above unity, one frequency grows on itself until it howls. The pitch is set by the resonant peaks of the room and the equipment. Engineers fight it by aiming mics away from speakers, cutting those frequencies and keeping gain just below the threshold. It sits in Mondo's music collection, one of 200 facts that each trace back to the reference below.

Where this comes from

Shure

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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More facts like this

Cardioid subwoofer arrays push bass forwardStacked subs fed with delay cancel low frequencies behind the stage Hormone levels are held steady by feedback loopsRising levels of a hormone usually switch off the signals that produced it The Shure SM58 became the standard stage microphoneThe cardioid dynamic mic arrived in 1966 and has barely changed since In-ear monitors replaced a wall of wedgesSingers once relied on floor speakers aimed up at them from the stage lip Delay towers carry sound to the far fieldExtra speaker stacks are timed to arrive in step with the main stage The same stage microphone has been standard since 1966The Shure SM58 is a budget dynamic built to survive being dropped

Tags: live-sound, feedback, acoustics

Feedback is a loop that feeds itself: the short answers

Where does this come from, and can I check it?: A microphone picks up a speaker, which feeds the same tone back louder. The figure is taken from Shure, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a music fact?: Yes. It sits on the Music shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.