Sound problems can be caused by anything from architectural defects to misguided equipment operators. Here are some of the most troublesome sound problems that churches struggle with and what can be done about them:
1. Echo, or excessive reverberation, can be the result of poor architectural design or timing variations between speakers. Timing problems occur in large rooms in which speakers face each other from different sides of a room. If a church has a long, narrow sanctuary and puts a speaker on the back wall, that speaker should have a slight sound delay. Otherwise, the sound waves from the front speaker will arrive at the back of the sanctuary after the rear speaker releases its waves. It's easier to place all of the speakers at the front of a room and adjust their volume and position to reach the back row.
Some buildings have flat, reflective surfaces that make sound waves act like bumper cars. For example, if a church holds a potluck dinner in a gymnasium or multipurpose facility with hard surfaces, table conversation will become a muddy hum that gradually increases in volume. A speaker's voice will bounce around the room. This problem can be remedied by hanging fabric panels, banners, or baffles on the walls or from the ceiling. Check what's offered at Acoustical Solutions http://www.acousticalsolution.com/ or Acoustics First Corporation http://www.acousticsfirst.com/ for off the shelf solutions and consultation.
2. Feedback occurs when amplified sound from a speaker or monitor circulates through a microphone and is amplified again, giving off an obnoxious squeal. This kind of sound loop is due to monitor placement as well as microphone technique. If a singer points a microphone directly into a monitor or if there isn't sufficient distance between the microphone and the monitor, feedback is inevitable. Feedback also happens when a speaker moves around on a platform, pointing the microphone in various directions. For churches with such speakers, several manufacturers offer a feedback controller that eliminates feedback by constantly shifting audio frequency.
3. Inadequate training. Sound equipment, no matter how costly, won't perform well if technicians don't know how to use it. After determining that a person has a solid interest in serving as a sound technician, work with the person until that person is qualified to serve. Invest in training materials such as books, videos and trade publications.
The best sound system can be compromised by a performer. A singer who holds a microphone far from his mouth, for example, forces a technician to turn up the volume on a channel, which could result in feedback. Singers should adjust their microphones according to the volume of their voices. On a high, strong note, the microphone should be moved away from the mouth; on a low, soft note, in closer.
4. Poor communication.Technicians must explain what they're doing to performers. For example, a performer might want more reverb in her monitor, but the sound technician knows that singers maintain better pitch quality without hearing reverb in the monitors. The sound technician could mix some reverb into the system and eliminate it in the monitor, but if the singer doesn't understand what the technician is doing, she will perform with less confidence. The moral for technicians is to be diplomatic. The moral for performers is to trust the technician.
5. Muddy sound. Inexperienced technicians are often plagued by muddy sound, which is quite often the result of monitor wash. For example, if the worship leader has a monitor on the platform, it is usually pointed at the back wall and away from the congregation. If the monitor is turned up too loud or includes too varied a mix, the sound will bounce off the back wall and collide with other sounds on the way to the congregation. The solution could be as simple as adjusting the volume of the monitor. If a worship team is large enough, it might need multiple monitors. Monitor mixing is an art that requires much practice, however.
6. Hot or dead spots. Hot spots are places in a room where sound energy is densely concentrated, and dead spots are where there is no sound. Both are usually caused by misplaced speakers. The laws of physics are the same in the house of the Lord as they are in Carnegie Hall. It doesn't matter how expensive speakers are; if they're situated incorrectly, they won't work properly. Speakers should almost always be placed by a professional or someone who understands room acoustics.
7. Noise. One of the secrets to maintaining high sound quality is isolating sound. Air ducts sometimes transport unwanted mechanical noise throughout a building. Exterior noise of cars, trains, or sirens can be intrusive if a church isn't well insulated. Noise problems can be averted most effectively when a church is being built, but there are ways to filter it out in existing buildings.
8. Poor installation. Churches should consult with professional sound technicians on the purchase, installation, and operation of sound equipment. A good sound company should have a list of recently completed projects and be willing to show them to you.
9. Misconceptions. It is critical for a church to define its need for a microphone before purchasing it. Microphones are like lenses on a camera. You choose them based on the effect you want. Frequency response, sensitivity, and impedance are key factors. High-impedance microphones produce noise (crackling, thuds) when moved or bumped. Mikes with lower-impedance—somewhere between 300 and 600 ohms—are better for churches.
Soprano vocalists often have high-frequency response in their voices and do not want a microphone with built-in boosts in the upper register. Male vocalists can get by with most microphones, but they'll do better with a boost in high-frequency response. For a good all-purpose microphone, consider a dynamic cardioid, which should cost from $100 to $150. Microphones designed to amplify a grand piano or an orchestra will cost more.
10. Budget miscues. A budget is not an accurate measure of what sound system a church should buy. Churches have been going to vendors for years, saying, “We have a $3,500 sound budget," and vendors have been giving them $3,500 sound systems. What church leaders don't understand is that a sound system can be purchased in increments over several years. Also, function is more important than price. Sound systems should be designed around usage factors such as what kind of music a church performs, how loud the music is played, and how large the church is.