Reducing Feedback: Simple Tips for Better Audio

In our last post, we discussed optimizing gain and EQ settings on an analog board to improve audio quality. Today, we’re focusing on a common challenge: feedback. These simple tips will help you achieve a cleaner, clearer sound for worship services without investing in new equipment.

1. Microphone Placement

Microphone positioning plays a big role in reducing feedback and boosting sound clarity. Here are a few placement tips:

• Position Mics Behind the Sound Source: To prevent feedback, keep microphones positioned behind the main sound source, such as speakers. This simple adjustment helps reduce the chances of sound looping back into the microphone and causing feedback.

• Encourage Close Mic Usage: Ask speakers and singers to stay close to the microphone. The closer they are, the clearer and more direct their sound will be, with less chance of picking up unwanted noise. Additionally, less gain is needed for close-mic setups, which helps reduce the risk of feedback and makes it easier to balance sound levels.

2. Speaker Positioning

Just like microphones, speaker placement affects sound quality and feedback. Here are a few guidelines:

• Avoid Pointing Speakers Toward Microphones: Place speakers so they’re angled toward the audience, not back toward the stage. This helps keep sound from bouncing back into the mics, reducing feedback.

• Raise Speakers Above Ear Level: Positioning speakers higher can help reduce reflections from walls and other surfaces, improving clarity for the entire room.

3. Using EQ to Manage Problem Frequencies

Certain frequencies are more prone to feedback due to the unique acoustics, or "room modes," of each space. Here’s how EQ can help:

• Identify Problem Frequencies: Feedback-prone frequencies vary by room due to its shape and surface materials. If feedback persists, use EQ adjustments to identify and lower specific frequencies.

• Cut Problem Frequencies on Each Channel: Start with a narrow cut (a slight reduction) on the EQ band that aligns with the feedback frequency.

• Make Adjustments at the Channel Level if Possible: It’s best to make EQ adjustments on individual channels to target specific sources of feedback without affecting the overall mix. If channel-level adjustments aren’t possible, you can make changes on the monitor or main L/R output, but keep in mind this will be a macro adjustment, impacting all sounds coming from the mixer.

• Use an RTA on a Digital Mixer: If you have a digital mixer, use the Real-Time Analyzer (RTA) tool to visually identify the frequency causing feedback. The RTA highlights spikes in real-time, making it easier to pinpoint and reduce problem frequencies.

• Make Small Adjustments: Avoid large cuts; subtle reductions are often enough to manage feedback without sacrificing sound quality.

By focusing on microphone and speaker placement and addressing problem frequencies with EQ, you can greatly reduce feedback and achieve a clearer sound during worship services. In our next post, we’ll dive into using EQ to address muddiness and further enhance sound clarity.