How to Avoid Feedback Howling in Stage Monitors
Stage monitor speakers provide floor foldback sound for the band on stage.
Optimizing gain before feedback (GBF) before graphic EQ is one of the most misunderstood aspects of PA systems. While stage monitors can be placed almost anywhere, the following tips can help you navigate the pitfalls and achieve higher GBF.
Even if your microphone isn't howling yet, you might hear a hollow, 'boomy' sound. While room acoustics can cause this, it's often due to the microphone picking up too much signal a second time and feeding it back into the system chain, leading to painfully sharp feedback howling.
Before diving into system optimization, mastering some fundamentals is essential. Understanding stage monitor placement requires knowledge of your microphone types.
Microphone Polar Patterns
Microphones are broadly categorized by polar pattern: omnidirectional and unidirectional. Omnidirectional mics pick up sound equally from all directions, making them rare for live sound. Unidirectional mics capture sound primarily from specific directions.
Cardioid Mic / Monitor Placement
Pointing a cardioid mic directly at a stage monitor is highly likely to cause feedback. Therefore, positioning the mic so its null point faces the monitor is often best—provided you're using a cardioid. Cardioid gets its name from its heart-shaped pickup pattern.
Supercardioid Mic / Monitor Placement
Looking at the supercardioid pattern, you'll see that pointing the null away isn't necessarily optimal, as supercardioids exhibit similar sensitivity directly in front and directly behind. The best placement for a supercardioid is slightly off-axis from the monitor. Using two stage monitors or angling the mic more directly towards the performer often yields better results.
Tip: If you need more gain, try polarity inversion.
1. Invert the polarity (phase) of microphones with strong level signals. Engaging the polarity switch on the mixer channel often helps significantly.
2. Often, inverting the polarity of the entire speaker system is more effective. Achieve this by swapping the positive and negative connections at the amplifier outputs driving the monitors. (Use appropriate cabling/adapters). While not universally applicable, this can frequently gain an extra 3dB of headroom.
These tips aren't about maximizing monitor SPL; we know excessive stage volume is undesirable. Applying this knowledge should help you effectively avoid the torment of feedback howling.
Optimizing gain before feedback (GBF) before graphic EQ is one of the most misunderstood aspects of PA systems. While stage monitors can be placed almost anywhere, the following tips can help you navigate the pitfalls and achieve higher GBF.
Even if your microphone isn't howling yet, you might hear a hollow, 'boomy' sound. While room acoustics can cause this, it's often due to the microphone picking up too much signal a second time and feeding it back into the system chain, leading to painfully sharp feedback howling.
Before diving into system optimization, mastering some fundamentals is essential. Understanding stage monitor placement requires knowledge of your microphone types.
Microphone Polar Patterns
Microphones are broadly categorized by polar pattern: omnidirectional and unidirectional. Omnidirectional mics pick up sound equally from all directions, making them rare for live sound. Unidirectional mics capture sound primarily from specific directions.
Cardioid Mic / Monitor Placement
Pointing a cardioid mic directly at a stage monitor is highly likely to cause feedback. Therefore, positioning the mic so its null point faces the monitor is often best—provided you're using a cardioid. Cardioid gets its name from its heart-shaped pickup pattern.
Supercardioid Mic / Monitor Placement
Looking at the supercardioid pattern, you'll see that pointing the null away isn't necessarily optimal, as supercardioids exhibit similar sensitivity directly in front and directly behind. The best placement for a supercardioid is slightly off-axis from the monitor. Using two stage monitors or angling the mic more directly towards the performer often yields better results.
Tip: If you need more gain, try polarity inversion.
1. Invert the polarity (phase) of microphones with strong level signals. Engaging the polarity switch on the mixer channel often helps significantly.
2. Often, inverting the polarity of the entire speaker system is more effective. Achieve this by swapping the positive and negative connections at the amplifier outputs driving the monitors. (Use appropriate cabling/adapters). While not universally applicable, this can frequently gain an extra 3dB of headroom.
These tips aren't about maximizing monitor SPL; we know excessive stage volume is undesirable. Applying this knowledge should help you effectively avoid the torment of feedback howling.