Optimizing Live Sound: Mastering Feedback Control with Feedback Hunter, X-FDBK, and PSE

In the realm of live sound, achieving the perfect balance between volume and clarity can be challenging, especially when dealing with feedback. Waves Audio offers three powerful plugins—Feedback Hunter, X-FDBK, and Primary Source Expander (PSE)—each designed to help sound engineers manage feedback effectively. In this blog post, we will explore the unique benefits of each plugin and provide a recommended workflow for using them to ensure the loudest and cleanest front-of-house (FOH) and monitor mixes.

Understanding the Plugins

Feedback Hunter

Feedback Hunter is your go-to tool for maximizing gain before feedback occurs. It processes the entire frequency spectrum, allowing you to optimize stage monitors before the show starts. This plugin replaces the traditional method of “ringing out” speakers, which involves manually identifying and addressing problematic frequencies. Feedback Hunter automates this process by generating a loud white noise signal and analyzing it to create an EQ curve that maximizes gain before feedback.

X-FDBK

X-FDBK is a versatile plugin that can be used both before and during a live performance. Unlike Feedback Hunter, which works on the entire frequency spectrum, X-FDBK targets individual frequencies that cause feedback. It dynamically identifies and notches out these frequencies, making it an essential tool for real-time feedback management during a show.

Primary Source Expander (PSE)

PSE operates differently from the other two plugins by focusing on mic gain rather than frequencies. It reduces the microphone’s gain when it is not in use, thus minimizing mic bleed and the risk of feedback. This is particularly useful for dynamic stage environments where performers move frequently or when multiple open microphones are used.

Recommended Workflow for Live Sound Optimization

Step 1: Use Feedback Hunter to Maximize Gain Before Feedback

Before the performers take the stage, use Feedback Hunter to prepare your wedges or PA system. This involves:

1. Running Feedback Hunter to analyze the monitors.
2. Allowing the plugin to generate a loud white noise signal and detect problematic frequencies.
3. Applying the continuous EQ curve created by Feedback Hunter to optimize the relationship between the microphone and the loudspeaker.

This process ensures quick stage preparation and maximizes gain before feedback, providing a solid foundation for the rest of the sound check.

Step 2: Use PSE to Reduce Mic Bleed and Minimize Feedback Risk

After setting up the stage, insert PSE on the individual channels of sensitive microphones. PSE helps by:

1. Attenuating the gain of microphones when they are not in use.
2. Reducing mic bleed into other channels.
3. Minimizing feedback risk by lowering the mic gain between vocal phrases.

This is particularly effective when the singer moves a lot or when you want to reduce stage noise without manually adjusting the faders.

Step 3: Use X-FDBK to React to Any Remaining Feedback During the Show

Despite your best efforts, feedback might still occur during a live performance. This is where X-FDBK comes in handy. To use X-FDBK effectively:

1. Engage the plugin during the show if feedback occurs.
2. Let X-FDBK search for sine wave-like feedback loops and notch them out with narrow filters.

This plugin is particularly useful for managing feedback caused by singers who cup the microphone or instruments with long sustain, such as pianos.

Comparing the Plugins

Feedback Hunter

• Method of Operation: EQ’s the entire frequency spectrum.
• Stage Bleed Reduction: No.
• Instruments with Long Sustain: Yes.
• Tonality/EQ Impact: Yes.
• Signal Chain Placement: Individual channels, auxes.
• Usage Time: Before soundcheck.

X-FDBK

• Method of Operation: Cuts specific frequencies.
• Stage Bleed Reduction: No.
• Instruments with Long Sustain: Yes.
• Tonality/EQ Impact: Yes.
• Signal Chain Placement: Individual channels, auxes, master channel.
• Usage Time: Before or during the show.

Primary Source Expander (PSE)

• Method of Operation: Attenuates mic gain.
• Stage Bleed Reduction: Yes.
• Instruments with Long Sustain: No.
• Tonality/EQ Impact: No.
• Signal Chain Placement: Individual channels.
• Usage Time: Before or during the show.

By understanding and utilizing Feedback Hunter, X-FDBK, and PSE, sound engineers can significantly enhance the quality of live sound. These plugins offer a comprehensive approach to feedback control, ensuring that your live events deliver the clearest and most impactful audio experience possible. Follow the recommended workflow and leverage the strengths of each plugin to achieve optimal sound quality and prevent feedback from disrupting your performance.