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

Mar 06, 2024

These three plugins will get you the loudest, cleanest FOH and monitor mixes—but each has its own advantages. Learn when to use each and for which purposes.

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

While X-FDBK, Feedback Hunter, and Primary Source Expander (PSE) all help prevent feedback, they do it in very different ways. Let’s explore their unique benefits.

First, let’s understand the main differences between how each plugin works:

  • Feedback Hunter is used before the show, and processes the entire frequency spectrum in order to maximize gain before feedback in general.
  • X-FDBK can be used either before or during the show, and processes individual frequencies that create feedback.
  • PSE does not process frequencies but rather attenuates the level of the mic when it is not used.

As you can see, each plugin offers unique and effective strategies to prevent feedback. But how do they complement each other, and what is the recommended workflow for using them in a live event?

For the ultimate protection against feedback, we recommended this workflow:

1. Use Feedback Hunter to Maximize Gain Before Feedback, by Optimizing Stage Monitors Before the Show

Before the performers arrive, use Feedback Hunter to prepare your wedges or PA. Feedback Hunter replaces the process known as “ringing out” the speakers, where the soundman manually searches for problematic frequencies that need to be taken care of. Ringing out properly requires a lot of time even after years of training.

Feedback Hunter will produce a loud white noise signal and analyze it (don’t forget to mind your ears and warn the rest of crew while you do that!) The plugin will detect any problematic frequencies and create a continuous EQ curve that optimizes the relationship between the mic and the loudspeaker. This will result in optimized speakers with maximum gain before feedback.

Feedback Hunter will help you achieve:

  1. Quick stage preparation before sound check: Feedback Hunter can analyze and process monitors in under 30 seconds, transforming a long and tedious process into one quick and trustworthy effort.
  2. Maximum gain before feedback: The EQ curve created by Feedback Hunter will maximize gain before feedback throughout the show in general.
Feedback Hunter

Run Feedback Hunter before the show, to maximize gain before feedback

2. Use PSE to Reduce Mic Bleed and Further Minimize Risk of Feedback

After having the stage ready for soundcheck, you can go further and insert Primary Source Expander on the individual channels of sensitive microphones. PSE is a noise gate designed for live stages, which reduces the gain of a microphone when it is not in use (for example, when the singer does not sing in-between vocal phrases). By doing so, PSE reduces mic bleed into other channels. It also reduces the risk of feedback, because no rogue signal gets fed into the loudspeaker.

PSE is especially useful when:

  1. The singer moves a lot and crosses the PA line: PSE will prevent the PA from feeding back whenever the singer is not singing by automatically lowering the mic gain between sung phrases.
  2. You want to reduce stage noise without riding faders yourself: By attenuating the gain of your open microphones between musical phrases, PSE makes sure you don’t get unwanted sounds coming through the microphones when they are not in use.
Primary Source Expander

Use PSE to reduce mic bleed and further minimize feedback

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

Despite the above precautions, feedback might still occur in extreme situations during the show. Our last guard against feedback is X-FDBK. Whereas Feedback Hunter is used only before the show, during setup time, X-FDBK can be engaged during a show, when problems come up unexpectedly. The plugin reacts to feedback loops that sound like sine waves (“pure feedback”): it searches for these sine waves as they appear and notches them out with a narrow filter, determining how narrow and how deep the frequency cut should be for the feedback to stop.

X-FDBK is especially useful when:

  1. You have a singer who cups the microphone and produces feedback while singing: X-FDBK will cut the offending feedback frequencies statically. (By comparison, PSE will attenuate the gain and help prevent noise and feedback only while the singer is not singing.)
  2. You have an instrument with long sustain, for example piano: X-FDBK and Feedback Hunter will both accommodate the instrument’s natural dynamics, feel, and decay time, whereas PSE might cut off the sustain on instruments with long natural decay such as the piano.

Use X-FDBK during the show, to eliminate remaining feedback

In summary, these three plugins offer unique and effective strategies to combat feedback in live shows and other events such as conferences. Together, they form a robust defense against feedback, ensuring your live events resonate with nothing but the best audio experience.

Here are the differences between the plugins at a glance:

Feedback HunterX-FDBKPSE
Method of operationEQ’s the entire frequency spectrumCuts frequenciesAttenuates gain
Reduces stage bleedNoNoYes
Good for instruments with long sustain (such as piano)YesYesNo
Affects the tonality/EQ of the sourceYesYesNo
Placement in the signal chainIndividual channels, auxesIndividual channels, auxes, master channelIndividual channels
When it is usedBefore soundcheck, when setting up the stageBefore or during the showBefore or during the show
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