One of the most annoying things for live performances or speaking engagements is a thing called feedback.
It usually happens when you place your microphone too close to the speaker or play your guitar directly in front of the amplifier. Feedback occurs when a sound loop exists between an audio input (for example, a mic or guitar) and an audio output (for example, a speaker system)
In this example, a signal received by the microphone is amplified and passed out of the loudspeaker. The sound from the loudspeaker can then be received by the microphone again, amplified further, and then passed out through the loudspeaker again. This can continue going around and around and create a loud piercing sound.
Not only does this damage your ears, but it puts your audience off in a hurry!!
There is so help out there to control feedback
The first thing you need to do is make sure that your room has been properly tuned. This is a process that is done during installation setup. A spectrum analyzer is used to graph the frequencies in your room and a 15 or 31 band graphic equalizer is then adjusted according to the results. This will put all the frequencies at the same level and will help you get more volume before you start getting feedback. It also gives you accurate sound in your room. To see our selection of products that will help control feedback Click here
Not all of us have the availability of a spectrum analyzer to scope out a room, so we have to rely on our audio engineer (someone putting their fingers on the PA controls) using either a parametric equalizer (normally found on a mixer's input channels) or a graphic equalizer (commonly connected between the mixer's outputs and the amplifier inputs to correct acoustical problems in a room or to address feedback issues).
Professional setups circumvent feedback also by placing the main speakers a far distance from the band or artist, and then having several smaller speakers known as monitors pointing back at each band member, but in the opposite direction of the microphones.
You can also turn down your treble on your amplifier. Too much treble invites feedback so don't have too much treble in your amplifier settings.
Another help is to turn the volume on your guitar up only 3/4. Don't turn your volume up full as this is invites huge feedback! Always leave a little room on your volume, so don't turn it up all the way. Only 3/4 and I guarantee you will reduce feedback at least 80% with this trick.
One other trick is to turn down the gain or distortion on your amp. When you play softly, you can turn your gain or distortion full. But when you start playing with some serious volume, turn your gain only 50%.
You will still get the same sound and distortion, but this is the trick to avoiding feedback from occurring when you play loudly.
Finally, if you're using an effects pedal, only turn it up 3/4 the way. Like your guitar -- always leave a bit of leeway as it offers more control over the sound and keeps your playing tight!
Remember this -- if you keep control of your volumes, you reduce the level of feedback and have a much tighter sound as an over all band. If you turn everything up full and try to rule the world -- you'll sound a mess and out of control.
Acoustic Guitar Feedback
Feedback can turn a delicate acoustic guitar passage into a screaming, earsplitting beast in the blink of an eye.No matter how good your guitar pickup is, if the overall volume in the room is high enough, your guitar may generate feedback. The box of your guitar is a resonant sound chamber. The energy from the strings drive this box, but so do sound waves coming from the room. Drums, other amplified instruments, screaming fans, all generate sound frequencies that can resonate within your guitar, and be amplified through your pickup.
The bottom line is that, with most acoustic guitar pickups, keeping the overall volume of all the instruments in the room as low as possible helps reduce the potential for feedback.
It is a well known assumption that anyone with a pickup in their acoustic guitar should have a pre-amp, either mounted on the guitar or as an outboard unit between the guitar and the amp. Wise use of the volume and tone controls on your pre-amp can help to reduce feedback.
Here is some advice:
1. Set the volume at the pre-amp as low as possible and get most of your volume from the amplifying system. This makes your pickup less sensitive to the overall volume in the room.
2. Use the tone settings on your pre-amp to control feedback. Every guitar has a harmonic resonance point. This resonance point will vary depending on the size of the sound chamber and the stiffness of the construction. On a given guitar, increasing the volume in this tonal range can generate feedback. Conversely, reducing the volume in this specific tonal range enables increasing the volume of the remaining tonal spectrum. So, if volume adjustment alone isn’t enough to stop feedback, experiment with your tone settings. Often, dropping mid-range frequencies is a good place to start. Also, a given room will react, sonically, in its own way; so you may have to experiment with these settings each time you play in a different venue.
Remember feedback is on stage and in the room with you.You can’t see it but if you’re not careful it will join in and start playing with you.Do a good sound check before every session and you will enjoy the evening.