DIOCESAN ADVISORY COMMITTEE
Helping to Care for our Churches
A CHURCH SOUND SYSTEM
The purpose of a sound system is to provide sound reinforcement and not to provide a public address system. Unless planning for one of the cathedrals or "greater churches" the system should be designed and balanced to produce sound which appears to come directly from the person speaking. It is not helpful for hearing, or understanding what one hears, if the sound seems to be ‘dislocated’. This is a specialist field and regrettably, the local hi-fi shop is not the place to start.
One of the most effective ways to improve audibility is to improve visibility. If you can see the speaker clearly, you will almost inevitably seem to hear him better, and certainly comprehend him better. (Remember that the profoundly deaf may need to lip-read).
Churches need to make some provision for those who have a hearing loss. There are two distinct, but interconnected, systems. First, a Loudspeaker System to increase the sound levels which will help those who have a hearing loss, but have no need for a hearing aid. It also allows people with quieter voices to take an active part in the spoken parts of the service.
Secondly, there is the Loop System which will enormously benefit those who have a hearing aid with a "T" switch. The great advantage of a Loop System is that the deaf will hear directly without interference, and it will also allow the volume on a Loudspeaker System to be reduced well below public address levels. The disadvantage of a Loop System is that once the deaf person has switched to "T", he will not hear anything unless it is transmitted through the loop. Anything, even asides and announcements, and, of course, music, must be broadcast through the system.
In a small church, so long as those contributing to the service speak up, there may be no need for a Loudspeaker System, but a Loop System is invariably required. Larger churches will require both.
WARNING - A sound system cannot improve the way things are said and is no substitute for preparation and clear speaking, and even rehearsing. But it will allow more people to communicate more naturally and still be heard by those with a hearing loss.
CHOOSING A SYSTEM
Think out what the needs are for people with a hearing loss, which is a large proportion of the population; this is a problem which increases with age.
Consult the Archdeacon and seek informal advice from the Diocesan Advisory Committee. Get a specification and quotation of cost from at least two audio experts or firms. Installation (but not alterations) of fixtures (i.e. amplifiers but not microphones) in listed buildings is usually VAT exempt; induction loops are zero rated when supplied to a charity. Consult your architect about the appearance and position of speakers and the routing of cables.
The choice of the equipment – the amplifier, mixer desk, cabling and the number and the position of speakers - is a highly technical field and should not be attempted by local enthusiasts – however good their domestic Hi Fi systems! Too many churches spend thousand of pounds and their new sound system is not fit for purpose. The kind of loudspeaker – the number, power and position of them is critical to the system working. Whereas data projection is straightforward, filling a large space with sound without echo and generating an evenly spread sound field without null spots is very difficult and highly technical. Please do not try and do it yourself.
The following gives an introduction to the different elements involved – so that you can enjoy discussing the system with the experts (and the PCC).
AMPLIFIER
The heart of any sound system is the amplifier which is usually made up of two units (which may combined in very small systems). The first part of the amplifier is known as the ‘pre-amp’ and this collects the different sound signals, adjusts them for tone and volume and mixes them together and feeds them to a range of outputs. The second unit is the power amplifier and this does the job of generating the signal which will drive the loudspeakers by multiplying the very small voltages of the line signals into a large enough voltage to drive the speakers. There are no controls on a power amplifier.
1.PRE-AMP – MIXER
Most churches now have a ‘Mixer’ pre-amp because it is so flexible. When choosing the mixer you should consider that you may require some, or all, of the following facilities, either now or later. The connections are called ‘lines’ (recalling how the cabling diagrams are drawn) and there are a range of ‘connectors’ to suit all kinds of sound cable.
- Line Inputs for several microphones - both fixed and radio.
- Line Input for the play-back of pre-recorded CDs (music/teaching courses, etc)
- Line Input for a projection system sound signal.
- Line Output feed for the loop system (which requires its own amplifier and aerial).
- Line Output for recording CDs (ministry to the house-bound).
Pre-amps can make large changes to the tonal balance of a sound signal which is very useful when a system is set up, for the sound coming out of the speakers is always distorted to some extent by the space in which the speakers are situated. ‘Trimming’ the tonal balance can compensate for the space distortions and help make the sound seem more natural.
2. POWER AMP
Power to drive sufficient line-source loudspeakers to cover all the church, including the choir, and possibly the church hall. The power needed is calculated by sound engineers.
More expensive amplifiers distort the sound less (so it seems clearer) and can go a bit louder without extra distortion.
SPEAKERS
Modern speakers need not be unattractive, though they are the most visible, and therefore likely to be the aesthetically difficult, part of the system. They need to be well sited and unobtrusive, wherever possible they should be coloured to match their background.
Column loudspeakers comprise a vertical arrangement of small loudspeakers within the cabinet allowing the sound to be directed or "thrown" very accurately. It is better to mount the speakers above head height and angled downwards so that the sound is projected further and more evenly. The angled mounting of speakers on nave columns should be avoided if possible.
MICROPHONES
The varied demands of worship may be met with fixed or radio microphones, or a mixture of both. A fixed microphone at the lectern is usually sufficient but if the lectern is often moved for different services, a trailing lead may be inconvenient or dangerous. A radio microphone would overcome these practical problems. This microphone can be left open (switched on) throughout the service to pick up music for the Loop System.
The effectiveness of a fixed microphone at the pulpit is limited and in addition will depend on the style of the preacher, and his need to turn while addressing a widely spread congregation. There can also be a visual problem about fixing microphones and goosenecks to beautiful and/or valuable antique woodwork. A tie-clip or halter microphone may be better.
At the altar it is possible to use a visually unobtrusive low-profile microphone. Additional microphone sockets may need to be sited at other places, for example, at the minister's prayer desk, at the font, in the nave for intercessions, at the chancel step for weddings. It is important that all present use, and also any possible future use, is considered.
The cabling of microphone sockets is now being replaced by reliable radio-microphones which offer great flexibility. There are two types of radio-mikes – the small clip mike with a separate radio pack and the hand held mike with a built in radio pack (which can easily fit into a microphone stand clamp. Most allow you to choose the radio frequency they communicate upon, and so you can run several radio-mikes at once – each on its different frequency.
LOOP SYSTEMS
Loop systems are most efficiently installed approximately one metre above or below ear level. If there is no dado rail which would conceal it, for aesthetic reasons consider the possibility of installing induction loop cabling below the floor. The initial provision of a simple test unit is recommended so that operators may readily check correct functioning of the loop system. Once again, technical advice is necessary.
FURTHER PRACTICAL POINTS
Cabling: Though small in size, cabling can have a detrimental effect on the appearance of the church if not sensibly routed and neatly installed. The employment of a capable electrician working in conjunction with the supplier of the sound equipment may well result in a more satisfactory standard of cable installation. The routes of cables should be carefully planned so that they are unobtrusive, concealed in roof and floor voids, or small trunking could be used. The trunking should be painted on completion to match the background décor. It is important that all the equipment should be sympathetically installed in the church.
Control equipment and housing: Should be sited and permanently installed towards the west end of the church, where the operator can hear and observe, and readily make any necessary adjustments. In order to accommodate the control equipment it may be necessary to reduce the length of a pew and provide housing to match the existing furniture. This in turn may require employing a specialist furniture/woodworker. Such consideration is a major item and will require prior consultation with the architect and DAC. You will need:
- Space for the safe storage of accessories like radio microphones, spare batteries, cabling etc.
- An adjacent power supply with 30mA residual current device (RCD) protection.
- Lockable security, and possibly a localised security alarm.
Internal aerials: Should be permanently installed as inconspicuously as possible.
Fans and fan noise: Select equipment which does not require an internal cooling fan. Silence is important in worship and fan noise increases with age due to a build up of dust, resulting in unbalance of the fan and consequential wear of the fan bearings.
Operation: To ensure reliability it is important that the sound equipment is operated and maintained by a small number of responsible operators (say 2-3) who should have similar average hearing faculties.
Safety: All power supplies to sound equipment and in particular to electric guitars should be from 30 mA RCD protected double pole switched socket outlets.
FACULTY APPLICATION
Full details of the proposed installation, including the position of cables, speakers and control gear, and the external appearance of the speakers must be submitted, together with a plan indicating these, catalogue photos of equipment and the contractor’s detailed quotation. Photos of the church with the proposed location of the speakers marked should also be provided.
This advice and information is given in good faith and is based on our understanding of the current law. The DAC cannot accept any responsibility whatsoever for any errors or omissions which may result in injury, loss or damage including consequential or further loss. It is the responsibility of the PCC to ensure that it complies with its statutory obligations.
DAC January 2009
