Live Sound Tips: Feedback Problems & Equalizers
Overview
Minimizing feedback while maintaining a modicum of sound quality isn’t easy. It’s basically an exercise in compromise. If you turn up any mic/speaker system enough it will feed back, no matter how much equalizing you do. With that being said, there are all kinds of tricks good engineers use to minimize feedback.
Know Your Microphones
Where to position microphones in relation to your monitors is critical. Make sure you know the polar pattern of both. Spend some time experimenting!
Dial in Problem Frequencies with Equalizers
A good parametric equalizer can better able you to dial in to the exact problem frequency and very tightly notch it out without a significant compromise to the overall sound quality of the system. Graphic equalizers are great. However, they generally just don’t get in tight enough for this type of precise work. You have to experience the results yourself to fully understand the benefit of being able to very accurately zoom in on a hot frequency like this, but it does take some skill.
Parametric EQs are great for finding the frequency range causing feedback.
Find the Problem Frequencies
Furthermore, in a typical live situation these problem frequencies can move around a bit. You don’t notice it that much when using graphic equalizers because they affect a broader band of frequencies, but with the small frequency ranges affected by a tightly dialed parametric things like moving a microphone stand a few inches, or the room filling up with people, or even a change in the relative humidity can change the hot frequency enough to render the parametric useless. If you have a full time monitor engineer (or a sound guy who can stay on top of the monitors) this is no problem, but if your band has to set and forget you need to be careful.
A good alternative in those circumstances are the feedback eliminators. These automatically chase ringing frequencies and make EQ adjustments accordingly. Sabine and several other companies make them, and they actually work wonders when used properly under realistic circumstances. Talk to your Sweetwater Sales Engineer for more information on those.
Feedback eliminators will find and adjust ringing frequencies for you!
Helpful Links
8 Essential EQ Tips for Live Sound
What is the Difference Between Dynamic and Condenser Microphones?
6 Must-have Mics for Live Sound
When you need help, Sweetwater has the answers!
Our knowledge base contains over 28,000 expertly written tech articles that will give you answers and help you get the most out of your gear. Our pro musicians and gear experts update content daily to keep you informed and on your way. Best of all, it’s totally FREE, and it’s just another reason that you get more at Sweetwater.com.
