Transcript
Worship Sound Pro 101 Guides 6. 6.
Optimizing Your
Monitor System By Mitch Mit itch c Gallagher ch Ga allla lagh gher gh er In order for your worship team to perform at their best, they must be able to clearly hear what they and the other members of the team are playing and singing. That’s the purpose of the monitor system onstage — to route signals from om vocals and instruments back to the worship team am so that they can hear everything. The problem is that the monitor system consists ts of speakers that are playing sound back toward the he microphones. And that’s a situation that’s fraught with peril — it’s a squealing feedback nightmare waiting to happen! But, there are techniques and tools that will help to optimize the sound quality of your church’s monitor system while preventing out-of-control feedback from intruding on your services.
Why Feedback Occurs Let’s begin by figuring out why feedback happens. It’s a matter of recycling: A sound enters a microphone. It’s sent through the sound system, amplified, and sent out of the monitors. The sound from the monitors enters the microphone, is sent through the sound system, amplified, and sent out of the monitors. The sound from the monitors enters the microphone, is sent through the sound system, amplified, and sent out of the monitors. The sound from the monitors…you get the point; the system has become a giant loop, known as a “feedback loop.” Eventually, the feedback loop swirls out of control, resulting in the obnoxious screaming squeal we all despise so much. So, how do we prevent feedback loops from happening? The key is to control the sound that is coming out of the monitors and how much of it gets back into the microphone or microphones.
Positioning Monitors and Mics
Cardioid polar pattern
The first line of defense against monitor feedback is correctly positioning the microphones and monitors in relation to one another. Most microphones that are used for live sound applications have what is known as a “cardioid” polar, or pickup, pattern. This means that they respond well to sound entering from the front of the microphone, pick up some sound from the sides of the microphone, and reject sound that is coming from directly behind the microphone.
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We can use this fact to our advantage to help reduce feedback problems. Position the monitor for each vocalist directly in front of them so that the sound from the speaker is aimed at the back of the microphone, where the sound rejection is the best. Try to position the various performers so that the microphones that are placed on acoustic guitars, electric guitar amplifiers, drums, and other instruments are not pointing into the monitors — as much as possible, keep the rear of any microphones aimed at the nearest monitors. This type of careful positioning will go a long way toward cutting down on feedback problems.
Ringing Out a Room Step-by-step The next thing we can do to prevent feedback in the monitor system is to control “hot” frequencies — frequencies in the stage area that tend to resonate or “ring” and are prone to feeding back. An equalizer, usually a 1/3-octave graphic equalizer, is used on the monitor system to control those hot frequencies and to shape the response of the system to reduce feedback problems. The process of setting up the equalizer is called “ringing out the room” and consists of just a few simple steps. Here’s how it works: 1. Clear the room of anyone not involved with setting up the system — feedback is no fun to listen to! 2. Make sure the equalizer is installed in the system and is set up to be used on the monitors. Set all the sliders on the equalizer to “0,” where they are not boosting or cutting any frequencies. 3. Turn on the system and get it ready to go, just as if you were preparing it for a service, with all of the microphones plugged in and ready to go, and the monitors turned on and ready.
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4. Turn up the volume on the monitors to a low level and make sure that all the microphones and speakers are on and working. 5. Slowly increase the volume of the monitor system until a frequency begins to feed back. 6. Find the offending frequency on the equalizer and pull its slider down until the feedback stops. At first, you will probably need to use trial and error to find the correct frequency. But, as you do this process, your ears will tune in to the general range of the frequency making it easier to find. With enough practice, you will be able to immediately identify the frequency that is feeding back. Pull the level of the frequency down enough to completely remove the feedback, but don’t pull it too far. If you remove too much of a given frequency, then the sound from the monitors will be unnatural for the performers.
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7. Increase the volume level of the monitors until another frequency begins to feed back. 8. Reduce its level on the equalizer to stop the feedback. 9. Repeat until the monitor system has reached a sufficient ent volume level and is not feeding back — normally adjusting the he level of four or five frequencies is plenty to get feedback under control. trol. Make sure you’ve allowed some headroom in the volume level so th tthat at there is no chance of a frequency feeding back at the volume levell aatt which the monitors normally operate.
Feedback Eliminators If the process of ringing out your room seems too complex, ex, or if you’r you’re ’re having difficulty getting your monitor system adjusted properly, roperly, then there is another solution: a feedback eliminator. Feedbackk eliminators are devices that combine the functionality of frequency analyzers and equalizers into one box. Basically, it makes the process off ringing out the room automatic. As you increase the volume of your church’s monitor system, the feedback eliminator will detect the onset of feedback, nearly instantly find the offending frequency, and reduce its level sufficiently to stop the feedback. If this seems like a simple solution to controlling feedback in your monitor system, well, that’s at’s because it is a simple solution, and it’s one that works quite well in practice. ractice. Peavey PV 12M
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Take Charge Once your monitor system is properly set up and its response prope properly perly adjusted, feedback problems should be a thing of the past. And, monitors unless you change something in the system or move the monito tors rs or with plug microphones around, you shouldn’t have to fo fool ol w wit ithh itit.. Ju Just st pplu lugg in the turn volume Should mics, turn on the system, and tu urn iitt up u ttoo th thee vo volu lume me yyou ou need. Shoul uldd ring you make a change to the system or o rreconfi econ ec onfifigu gure re the stage, just rin ingg th the feedback eliminator room out again or run your feedbac ackk el elim iminator through iits ts ddetection etec et ecctition onn process again. feedback-resistant system willlll m make A great-sounding, feedback-resista tant nt monitor or sys yste tem m wi w akee fo ak forr speakers a happy worship team and for spe peak aker e s wh whoo ar aree ab ablee ttoo pe pperform rfor rf orm or m an andd system getting inspire the congregation without ut w worry of th thee sy syst stem st em gget ettititing et ng oout uutt ooff service congregation control or of feedback ruining a sser ervice — aand ndd ffor or a ccon ongr on greg egat eg atio at ioon th that at coming through sound system. isn’tt subjected to painful squeals is ls ccom omin inng th thro roug ro ughh th ug thee so oun u d sy ysttem em.. It It’s’s win-win involved! aw inn win situation for everyone ne iinvol olve ved! d!
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