How to Stop Microphone Feedback Fast: A Guide for Church Sound Volunteers

Microphone feedback is a common challenge in church audio systems, especially for volunteers who are just starting to navigate the complex world of sound engineering. This guide is designed to demystify the process of eliminating feedback and ensuring a clear sound for your services.

Understanding Feedback

First, let's understand what feedback is. Feedback occurs when the sound from the speakers makes it back into the microphone, is amplified, and then sent out through the speakers again, creating a loop. This often results in a high-pitched squeal or howl that can disrupt your service.

Quick Fixes to Stop Feedback

1. Reposition Microphones and Speakers: Ensure that microphones are not directed toward speakers and are positioned behind the main PA speakers. This reduces the chance of sound from the speakers being picked up by the microphones.

2. Lower the Gain: Sometimes, feedback is simply a result of the microphone being too "hot" or sensitive. Lower the microphone gain on your console to reduce sensitivity without compromising on the clarity of the person speaking or singing (shoot for your input levels being around -18 on each channel).

3. Use Directional Microphones: These microphones pick up sound from a specific direction and are less likely to pick up ambient noise, including speaker output.

4. EQ Adjustments: Use the equalizer (EQ) on your soundboard to cut frequencies that are prone to feedback. Often, feedback occurs at specific frequencies. By identifying and reducing these frequencies, you can minimize feedback. If you are using a digital console, you can likely identify these frequencies using the built-in RTA meter on each channel's EQ. 

Step-by-Step Guide to Eliminating Feedback

1. Identify the Problem Frequency:

   • When feedback occurs, quickly identify which microphone is causing it. This might require a bit of trial and error, but with practice, you'll get faster.
   • Use a graphic equalizer to pinpoint the problem frequency. You might need to adjust the EQ on the fly during services, so it's essential to become familiar with your soundboard's EQ section. The RTA meter is your friend! It's not cheating, use it! 

2. Adjust the Equalizer:

   • Once you've identified the problematic frequency, reduce its level on the equalizer. Start with a narrow bandwidth and increase if necessary. Be careful not to overdo it, as too much EQ can affect the sound quality.

3. Test and Refine:

   • After making adjustments, test the microphone to ensure the feedback has been eliminated. It may require several attempts to completely remove feedback without compromising sound quality.

4. Monitor Constantly:

   • Feedback can occur at different times and with different microphones. Keep an ear out for any signs of feedback and be ready to make quick adjustments.