Show dictionary · Audio
Feedback
Feedback is the self-sustaining howl produced when a microphone picks up the sound system’s output and the system re-amplifies it in a loop. It rings at whichever frequency completes the loop with the most gain, from low growls to glass-cutting squeals.
In practice
The loop gain story explains every cure: reduce the gain (turn it down), break the path (move the mic or speaker, aim wedges past the mic’s pickup pattern), or cut the ringing frequency (EQ notches). "Ringing out" a system pushes gain until it just rings, notches that frequency, and repeats, buying usable gain before feedback.
Directional microphones, in-ear monitors, and disciplined mic technique are structural defenses; the performer cupping a mic in front of a wedge defeats all of them at once. Every live engineer keeps a mental map of which frequencies the room wants to ring.
How you’ll hear it
"That ring on the podium mic is 2.5k; notch it in the wedge send before she starts."
Related resources
Part of the eventools.io Show Dictionary, a free glossary of live event production terminology.