Feedback FAQ/Plain
Feedback FAQ
What causes microphone feedback? Feedback happens when the sound from the loudspeaker is louder at the microphone than the performer’s voice. If the microphone “hears” more speaker than performer, the system will feed back.
For a full explanation and diagrams, see Feedback / Microphone.
How do I set gain staging to reduce feedback?
Set your source at its loudest performance level, then raise the Trim until you get solid green with occasional yellow (never red).
Once Trim is set, use channel volume for mixing — not Trim.
Details for T4S/T8S: Gain staging on the T4S/T8S follows the same principle: set input Trim so the input meter shows solid green with occasional yellow peaks. Avoid red. Then use channel volume and master volume for mixing.
Details for T1: The T1 uses a similar approach: set Trim so the input meter shows healthy signal without clipping. Use channel volume for mixing.
For more detailed steps for T1, T4S, and T8S, see Feedback / Microphone#Gain Staging.
Microphone Technique
Use close‑microphone technique: lips barely brushing the windscreen.
Every halving of distance gives roughly 6 dB more gain before feedback.
Close Microphone Technique details: Close‑miking increases the ratio of voice to ambient sound, improving gain‑before‑feedback and reducing the need for excessive system volume.
For more, see Feedback / Microphone#Close Microphone Technique.
Do directional microphones help with feedback?
Yes.
Supercardioid and hypercardioid microphones provide the best gain‑before‑feedback, followed by cardioid.
Omnidirectional microphones provide the least.
Details about Directional Microphones: Directional microphones reject sound from specific angles, reducing the amount of loudspeaker output entering the microphone. This increases gain‑before‑feedback and improves clarity.
For examples and diagrams, see Feedback / Microphone#Directional Microphones.
How should I place monitors to avoid feedback?
Monitor placement matters.
Place monitors in the microphone’s rejection zone (typically directly behind a cardioid mic, or slightly off‑axis for supercardioid/hypercardioid mics).
Avoid pointing monitors directly at the microphone.
For diagrams and examples, see Feedback / Microphone#Monitor Placement.
How many open microphones can I use before feedback becomes a problem?
Every time you double the number of open microphones, you lose about 3 dB of gain before feedback.
Use as few open mics as possible, and mute or gate unused ones.
See Feedback / Microphone#Open Microphones.
How should I use EQ to reduce feedback?
Use EQ sparingly.
Avoid excessive high‑frequency boost.
Use ParaEQ to notch out problem frequencies if needed.
For step‑by‑step notching instructions, see Feedback / Microphone#Notch Out a Problem Frequency.
Do vocal effects increase feedback?
Yes.
Effects such as reverb, delay, and chorus can reduce clarity and increase the likelihood of feedback.
Turn off effects until you have stable gain, then add them back one at a time so you can hear their impact.
See Feedback / Microphone#Effects.
Do instrument pickups help reduce feedback?
Yes.
Pickups provide much higher gain‑before‑feedback than microphones and avoid the distance and positioning issues of miking an instrument.
See Feedback / Microphone#Instrument Pickups.