How much power?

"How much power (wattage) do we need in our church sound system?"

This is a great question, and partly depends on the physical layout of the church, the decor inside and especially the style of worship and requirements from the sound system. However there are some rules of thumb....

Let us start at the top figure... a rock concert ... you need around 10W per person in the venue (generally speaking the number on the fire regulations). So for a 40 person venue such as a village hall you need around a 400W system.

With different styles of music however, you need less power - we typically put in 150W or 250W systems into churches, and augment this with a 150W sub-speaker (for low frequencies) if there is a band. There are obviously more than 30 people in a typical church, but in general churchgoers are not looking to be blown away!

In an outside event you need to probably double the output power because of the lack of reflections from the walls - outside sound just disappears.

"Should the speaker rating match the amplifier rating?"

Great question. The biggest cause of damage to speakers is the use of an amplifier which is not highly rated enough. As you keep turning up and up the amplifier level to get more sound, internal clipping occurs and this can be very bad for the speakers (it also causes headaches in those listening to the sound, even if the speakers are not damaged).

So, again as a rule of thumb, your amplifier should have a higher rating than your speakers. If the speakers have been chosen properly to match the room, the amplifier will never need to be turned up to maximum and therefore everything in the system remains happy.

If you are really worried, it is inexpensive these days to add a device called a "limiter" which ensures that the speakers cannot be overdriven. This is done in such a way as to also ensure that the loud signal remains musical.

Hope this helps!

Tim.

***** Visit us online at www.ChurchPA.co.uk *****
***** Phone 0845 430 9486 *****
Make sense?

Echoes are too much!

Hi All,

Again we have been contacted with the age old question which crops up in older churches, especially parish churches. We quote....

"The acoustic [in our church] are extraordinarily good for music and singing; but the same qualities make it difficult sometimes to distinguish the spoken word clearly. Deaf people in particular have great difficulty in making much sense of the sermon etc. "

In an old church it is very difficult to control reflected sound without drastically altering the look of the building. In some churches it is possible to remove the pews and put down carpeting, which makes a huge difference. This will not be an option for most older church buildings! In a smaller way, hanging banners can be a way to get more sound absorbing material into a church in an "unobtrusive" way (these should be made of the heaviest possible material... see our post on sound deadening)

Adding a hearing aid induction loop obviously does not help those without hearing aids (with the following exception), but is amazingly helpful to those with a suitable hearing aid. The minister wears a radio lapel microphone which obviously captures the spoken word "at source" without any echo. A microphone is also generally sited at the lectern so that occasional readers are also clearly picked up. These microphones are connected to an induction loop amplifier, which in turn connects to a loop of cable run discreetly and securely around the room. Those inside the loop with a hearing aid pick up the speech in an amazingly clear way. Additionally, the loop amplifiers have built in "gain control" circuitry which ensures that even if a loud or a quite person is preaching, a crystal clear sound reaches the user.

We also supply loop listeners, which are a small battery powered unit, like a Walkman with headphones. These pick up the signal from the loop and amplify it for the headphones. These can be given to users without a hearing aid, but who are having difficulty hearing the spoken word. The unit provides the user with a volume control so that they can have the sermon as loud or as quiet as they like!

Finally, in some churches, the use of small speakers correctly placed can help to balance out the sound in a church. This can be especially useful if there are "dead spots" in the church.

Technology really can help in older buildings to help everyone hear the word of the Lord. It does not need to be expensive, and with the correct equipment and installation techniques can be almost completely unobtrusive.

Hope this helps!

Tim
***** Visit us online at www.ChurchPA.co.uk *****
***** Phone 0845 430 9486 *****

Training Morning - Great Success!

Thanks to all who came to the training morning, and thanks also to the host church, St Matthew's.

Some of the feedback comments we had were....

"Good explanation of components of system across the board"
"We will now look more closely at the positioning of our microphones"
"Enjoyed the whole session"
"Very useful and informative morning"

Thanks again to all involved - we had a great time and look forward to our next session.

Tim.

***** Visit us online at www.ChurchPA.co.uk *****
***** Phone 0845 430 9486 *****

Training Morning

We are looking forward to our training morning on the 14th May in Cheltenham. On this day we will be covering topics such as:

• Microphones, how to position them and use them best
• Cables, how to treat them nicely, and our special coiling technique
• The mixer - channel strips and how to use them effectively
• The mixer - aux sends
• The mixer - centre section controls
• Induction loop, how it works and how you can check it is working properly
• Outboard equipment - CD, CDR, Tape, EQ, amplifiers
• Speakers
• Problem solving - broken microphones, radio microphone battery failure, FEEDBACK, no sound from the desk
  

Sorry that there are no more places available for this session, but if you or your church would benefit from having or hosting a training day with ChurchPA then please get in contact!

Tim.

***** Visit us online at www.ChurchPA.co.uk *****