How do microphones in live concerts not get a lot of feedback from all the noise? Microphone feedback is never a welcome event, whether you’re a singer, speaker, technician, audience member, or even a home hobbyist. Consequently, preventing and eliminating microphone feedback should be paramount when performing any live sound reinforcement.
Microphone Feedback: What Is It?
Let’s define microphone feedback first. Audio feedback between a microphone, which serves as an audio input and audio output is known as microphone feedback (often a loudspeaker or monitor). The mic signal is amplified and sent via the loudspeaker in a positive gain loop gain. The microphone then picks up the sound from the speakers and amplifies it further.
This cycle continues until the mic channel overloads, and the loudspeaker starts to screech horribly. How do microphones in live concerts not get a lot of feedback from all the noise? Feedback from the microphone is almost always undesired. A few situations come to me when mic feedback would be appreciated. This distinguishes it from other auditory feedback loops inventively used in music and other artistic mediums, such as guitar amplifier feedback. So, a microphone and a loudspeaker are needed for microphone feedback (this can be a speaker, headphones, etc.).
Increasing or Amplifying the Microphone Signal
A mic signal’s risk of feedback will grow with excessive amplification applied. Gain and amplification are necessary to make a microphone’s signal stronger and enable it to play through the loudspeaker at a suitable volume. There are two gain stages for the microphone signal to pass through in live sound reinforcement: How do microphones in live concerts not get a lot of feedback from all the noise?
Mic to line levels (gain applied at the mic input of a mixer or other audio device). Speaker level to line level (gain applied, so the signal is strong enough to move the loudspeaker diaphragm properly). Gain must first be set to ensure the signal is distortion-free (no clipping). Determining a microphone’s gain before feedback within your sound system makes sense. After it has been discovered, reducing the gain to a safe level below the gain-before-feedback threshold.
The loudspeakers’ volume
How do microphones in live concerts not get a lot of feedback from all the noise? The loudness or volume of the loudspeakers significantly affects microphone feedback, much like effective gain staging. The amplification of the post-mic-gain signal, which we touched on in the previous section, is what the “volume of the loudspeakers” refers to. It is nevertheless necessary to restate it here.
Let’s say all the levels are good, and the microphone(s) are working properly in the mix, but you’re still getting feedback from the microphone. In this instance, the loudspeakers’ total volume is probably too high for the room’s acoustics. Thus it should be lowered to assist in lowering or eliminating the chance of microphone feedback.
Recommended Article: Are Condenser Microphones Good for Live Stage Performances?
Distance Between The Loudspeaker And The Microphone
Gain-before-feedback depends heavily on the distance between the microphone and the loudspeaker. Since the distance between the nearest speakers and portable microphones frequently fluctuates, it is especially crucial to consider this.
How do microphones in live concerts not get a lot of feedback from all the noise? Generally, the sound waves from a playback source—in this case, a loudspeaker—are stronger the closer a microphone is to it. Greater sound waves produce greater mic signals. This will guarantee microphone feedback.
Microphone Frequency Response
The frequency response of a mic affects feedback to the extent that it merits noting here. Wide frequency ranges can be captured with condenser microphones, which frequently have flat frequency responses. Theoretically, this increases their sensitivity to microphone feedback throughout the audible frequency range.
How do microphones in live concerts not get a lot of feedback from all the noise? The entire spectrum of audible frequencies is frequently not covered by microphones with colored frequency responses (many dynamic mics have colored responses). Theoretically, this reduces their susceptibility to microphone feedback.