Do you have a feedback problem? Or does your sound system produce a hollow sound?
Does your cassette recording sound hollow, or do you hear a lot of audience noise instead of the pastor?
All of these symptoms could be caused by having too many microphones turned on. In sound systems, the fewer microphones that are on, the better the sound will be. In fact, no microphone should be on unless it is actually being used.
Any microphone that is turned on will be picking up whatever sound waves pass the microphone capsule. If it is only picking up unwanted noise and reflections, that is what will be mixed with the desired signal (say the pastor’s voice). This mixed signal will then be reproduced by the loudspeaker system or recorded on the cassette tape. The unwanted noise can make the cassette recording sound hollow. It can also decrease the intelligibility of the sound system.
There is another large benefit for keeping unused microphones turned off. You will be able to get more volume before feedback occurs. If you are having a feedback problem, first make sure that all the unused microphones are turned down or switched off.
There are three methods to accomplish this:
You can do this by training everybody to use switches on the microphones. This works well if everybody remembers to do it.
Unfortunately, someone will forget to turn on the microphone under the stress of public speaking. Another common problem will also likely occur. The talker will forget to turn the microphone off. Then the next user will really turn the microphone off when they try to turn it on.
A sound operator can turn the microphones on and off as needed via channel controls on the mixer. The advantage of this style is that the volume can now be adjusted for each talker or singer.
This is the best, and really the only way to adjust and balance for music. For example, in a situation where the keyboard seems too loud for the soloist, a sound operator can adjust the levels to an appropriate mix. The relative level between singers and instruments require a human touch with a musician’s ear.
A third method is to use an automatic mixer. This type of mixer automatically senses when someone uses a microphone and turns it on. This system works excellently for speech. An automatic leveler can be added to adjust the volume to keep the speech volume consistent.
If you want to get the best sound out of your system, you must use one of the above three methods of operation or a combination. For instance, the automatic mixer could be used for speech along with a sound operator for the music.
The method you choose will be dependent on your particular church and your needs.
Mixer – Tone Controls
Tone controls can help make a mix sound full. But, they can also cause a minor disaster for the inexperienced. Practice and knowledge of tone controls will help you develop the skill to create a wonderful mix. This column is about mixers with tone controls on each channel or input. Even if your mixer doesn’t have channel tone controls, please continue reading – there will still be information to help you with your mixer.
What are Tone Controls?
Tone controls are basically used to boost (increase) or cut (decrease) the response of certain frequencies. They are very similar to controls found on most home stereo systems. The tone controls on sound mixers are often called equalization (EQ) controls. Mixers have several EQ control designs: a two-band EQ has bass and treble controls; if the EQ has 3 controls, they are low, mid and hi controls; or, if you are fortunate enough to have a four-band EQ, they are low, low-mid, hi-mid and hi controls.
How to Use Tone Controls
Here are some guidelines for setting and using EQ controls.
Use EQ sparingly! Too often it is abused. If all the EQ controls on a channel are boosted more than 3 dB (approximately 2 or 3 o’clock), return all the EQ controls to zero (flat or 12:00) and try increasing the volume control. It will probably sound better and you will have less feedback problems. The same principle applies for cutting.
In general, cut the frequencies that are too loud. If a voice has too much bass, first try cutting the bass rather than boosting the highs. If you have a mid-control, you may achieve a better result by gently adjusting two adjacent controls rather than drastically cutting or boosting one control.
Tone controls affect a broad band of frequencies. Excessive boost or cut may degrade the response of a microphone or instrument. If you use the EQ controls to remedy feedback problems, be very cautious (use your ears). A slightly lower volume may actually be better than an unnatural sound caused by too much EQ adjustment.
Tone controls should not be used to improve the speaker system/room response. The system equalizer is designed to do that job. You need to make sure your speaker system is properly designed, installed, and adjusted. Also, the tone controls cannot improve the acoustics of a room. Problems with acoustics can only be fixed with physical acoustical treatment.
If you hear a “funny sound” from a microphone, try repositioning the microphone. You may be hearing the result of a reflection combining with the original sound. This can especially be a problem with a pulpit or lavalier microphone.
These items all point to a general rule-of-thumb when using tone controls on any mixer: They are the last resort in the attempt to compensate for sonic problems!
EQ controls can be used for: subtle enhancement of sound, to make a sound more natural, or to change a sound to achieve a special effect.
In closing, here’s a tip on creative use of tone controls: during a musical performance you may want to highlight a certain vocalist or instrument.
Rather than use the volume control, use a small amount of EQ boost in a strategic frequency range of the source. For instance, boost the treble controls of the piano microphone to enhance its upper harmonics. This method will create a more subtle change in the apparent presence (the feeling of being closer or in front) of the piano in the mix without the perception of a “solo” being added.
Keep practicing! And don’t forget to listen.