The successful installation of sound reinforcement systems in church is a combination of many factors.

Virtually any amplifier/loudspeaker/microphone combination will work in a church, but there is a vast difference between a system which just works, and one which works successfully in a variety of circumstances, over long periods of time and without requiring frequent adjustment or service.

CHOOSING EQUIPMENT

When choosing equipment, we suggest the following points be considered:

1 . Contrary to popular belief a church environment is one of the most difficult in which to operate a Sound System. Because of this, inexpensive equipment which appears to be suitable when viewed in terms of brief written specification, often fails to meet expectations when installed, and is frequently difficult or impossible to match satisfactorily to other equipment in the same system.

2. Long term reliability of operation is of great importance and equipment of a reputable make will rarely require any attention. Should it fail, however, the availability of spares must be considered. How easy will it be to obtain spares in say five years' time?

3. The Sound and Communications Industries Federation specifies minimum standards for equipment and installations. We would advise the choice of equipment which conforms to these requirements. Briefly, those applicable are as follows:

a)     Microphone circuitry should be of a low impedance balanced line type to avoid
          crackles, hums or interference.
b)     Microphone cables must be two core with a screened outer braid.
c)     Amplifiers should have an output at 100 volt line level. This allows long cable runs
          with minimum power loss, and also allows the loudspeakers in the circuit to be
          adjusted individually for output power. This may be necessary to correctly balance
          the system.
d)     Amplifiers should have both BASS and TREBLE tone controls, a single tone
          control is seldom effective.
e)     Loudspeakers for use in difficult acoustic conditions should be column or line
          source type. This is, a series of loudspeakers one above the other in a suitable
          cabinet. Generally, the greater the number of loudspeakers, the more directional
          is the sound from that column. The choice of speaker size to suit the room
          involved, and the length and width of sound throw is critical to the success of
          the system.

4. Loudspeakers should be mounted so that they direct as much sound as possible onto the congregation, and as little as possible into the room itself.

They should be positioned so that the sound appears to come from the person using the microphone. If the sound is allowed to reflect around the room, or if the room is simply filled with sound then results will be poor, will not appear to come from the person using the microphone, and acoustic 'howl' or feedback may be a problem.

5. The choice of microphones is of great importance, never 'save' money by buying cheap microphones, and always enquire about the spares situation in the event of damage. It can be very easy to knock a microphone off its stand or drop it accidentally.

Microphone connections should be robust and easy to plug in. XLR connections are recommended. These also have the useful quality of being easy to extend as the plugs and sockets link together and are very robust. Microphone leads can then be kept short to avoid messy loops of cables, but an extension lead can be kept available in the event of special occasions requiring a longer cable.
[Back to Top]

ACOUSTIC FEEDBACK

Acoustic Feedback (or howl) should be avoided in church, at all costs. Feedback is caused by sound from the loudspeakers reaching the microphone.

Careful choice of equipment together with care in microphone positioning usually overcomes the problem. There is, however, special equipment available to assist in feedback reduction. The 'frequency shifter" or 'stabilizer' is very effective in speech systems, but it may not be suitable for accompanied vocal use. The Shifter is very easy to set up and will not require adjustment once installed.

The graphic equalizer is another piece of equipment often used and although it is more difficult to set up it can be used for vocal sound reinforcement. A combination of both types can be used for severe cases of feedback or where the user needs to be a considerable distance from the microphone.

A question we are often asked is 'How far away will the microphone pickup?" The answer depends, invariably, on the feedback stability of the overall system, but the performance of the microphone itself is critical as is the choice of loudspeakers.

We trust that brief though it is, this page has been of help. Please remember that every installation is different and we would always advise that professional help be obtained before commencing work on the installation of sound equipment.
[Back to Top]