"Ringing out" the monitors is an expression that describes the technique of locating and adjusting the frequencies most prone to oscillation in the stage environment to achieve the highest possible gain before feedback. Assuming you have set up the stage to your advantage as we discussed in Part 1, you should already have a good start towards achieving loud, clean monitors without feedback. Now it is time to optimize (or 'ring out') those monitors!
Remember that we talked about how sound is directional and can reflect off of surfaces in the room? Because of this everything on stage (including the musicians themselves) function as reflectors potentially contributing to creating a signal loop (feedback). So if possible, begin with all your players onstage in the spots they will take up during the show. This is a very good time to utilize your hearing protectors by the way - your players all use hearing protectors, right? In order to get rid of potential feedback you need to force it to happen at the sound check.
Start with a Level Playing Field
Give yourself a nice clean start by setting all your equalizer settings to zero. The equalization that worked in the last club (or even last night in some cases) won't necessarily work in your present situation, so start out with the EQs set "flat" with all the controls back at center. At best taking shortcuts will give you "not terrible" results. There is no substitute for doing this every time you set up on a new stage, if your goal is to achieve optimal stage monitoring. Using a graphic EQ for ringing out the monitors is the best choice. Then you can use the mixer’s channel EQ for tone, and many times the mixer’s channel EQ does not affect the monitor sends. Be sure to not be counterproductive turning up a frequency on the channel that you are trying to cut in the graphic EQ.
Make sure all the mics are switched on and the monitors are at nominal levels. This is important, because the entire monitor system interacts with itself. If you don’t have something on during sound check you will get a surprise during the show. Begin by slowly increasing the volume of the monitor you want to optimize until you notice it is beginning to feed back slightly. Rushing will only cause painful levels of feedback that will likely offend whoever is working around you during sound check, but if you go slowly and listen carefully you should be able to detect a slight ringing just as the signal loop begins to oscillate. Remember feedback is telling us which frequency needs to be lowered? When you hear that ringing, try dipping your equalizer at the frequency of the oscillation. Make the smallest adjustment that corrects the feedback; don't over-do your equalization! Another trick you can use if you think you know the frequency is to turn up the monitor and work with the graphic EQ. Here you slightly increase the EQ frequency band level to see if it increases the feedback. If you can initiate and terminate the feedback by moving a particular fader on your graphic EQ you have found the offending frequency or at least one of the offending bands. Adjust as needed, but avoid over-compensating because extreme EQ settings can make the audio signal sound unnatural. Also as mentioned in Part 1, turning down most of the bands on the graphic EQ is not helpful if you need to turn up the volume again to hear it. This is turning your graphic EQ into a simple volume control.
At first it will seem like a guessing game, but with experience both you and your musicians will start to recognize the offending frequencies. This is a great reason to tell the players onstage which frequency was ringing, because it will teach them to recognize the various frequencies as well, and will make them more valuable assets during future sound checks.
Repeat the Process to Eliminate All the Remaining Feedback Frequencies
Once the signal loop is no longer feeding back, raise the monitor volume once again until another frequency begins to feed back. Find the new frequency and dip it also, continuing to increase the volume of the monitor and dipping each feedback frequency until you start to get feedback at multiple frequencies all at once. When this happens you have reached unity gain on that monitor. That is all the level you can get out of that monitor without feedback, of course complaints from your more hearing-impaired band members notwithstanding. Imagine the air onstage is "saturated" at this point and "can't hold any more sound pressure." This isn't entirely accurate strictly speaking, but it is a good way to visualize that you have no more gain available on that part of the stage. Reduce the volume of the monitor a few dB to put it well below the feedback saturation point. This will give you some headroom during the show. Now move to the next monitor channel. If the performer still isn't satisfied with their monitor level you might try relocating the monitor closer to their ears or move an offending microphone. You will have to start the ring out process over on that monitor channel if you change anything.After you have finished 'ringing out' all of your monitor channels have the band play a song at their normal performance level. Odds are that someone in the band will complain they "need more monitor." Try this old sound tech's trick to satisfy your most demanding performers: Take careful note of the exact volume setting on that player's monitor. Tell your performer you're going to "reset the monitor" and have them provide a test signal. Turn the monitor all the way down and slowly bring it back up to just below that previous level. Inevitably the player will say, "That's pretty good, but can I get just a tiny bit more?" Finish raising the monitor to its previous level. This will usually satisfy most performers, since they asked for more and got it, and the process of turning the monitor down and back up again allows the musician's ears to 'reset' so they can perceive the true level of the monitor. Sometimes the process of 'ringing out' can disrupt the performer's perception of volume in the same way it takes a few seconds to hear again after a loud jet passes overhead. Plus, if you did get a few strong feedback signals during ringing out, everyone needs a reset.
The more carefully you set up and adjust your sound system the better your results, and the less headaches you'll develop in the process. Always focus on the basics, because a solid foundation is the secret of building a great sounding show. What are your experiences and tricks to good monitors and ringing out the system? Let us know in the comments.