ChurchPA

We get feedback/howling in our church

2008-01-09T08:18:00.000Z

It is very difficult to use our sound system, which is around ten years old, because if we turn up the level to something which people can hear, we get horrible howling sounds from the speakers. I´ve been told this is called feedback. Can you help?

Feedback in a sound system only occurs when the sound coming from speakers re-enters through a microphone and is then amplifed again and again.

Therefore the most common cause of feedback is that the microphones are somehow pointing at a speaker or a very direct wall reflection from a speaker.

Solution: ensure that no microphones are pointing directly at any speakers, and be very careful of omnidirectional pickup (all directions) as you are asking for problems!

The second most common cause is that the amplification (or gain) of the system is too high. In churches this is common if the speakers are inefficient or pointing in the wrong direction, or the wrong type of speaker. This forces the level to be turned up to compensate and will eventually lead to feedback.

Solution: if you have older speakers, consider installing modern speakers with a well defined coverage pattern (such as the JBL Control range of speakers). Often this can be a straight swap for your existing speakers. Turn down the level at the mixer a little too, and if you have tone or EQ controls then try to reduce the level at problematic frequencies.

The third most common cause is the wrong type of microphone. Very often, churches use vocal/singers microphones for lectern and readers microphones. Vocal mics are designed for efficient pickup at about 2 inches, but users at a lectern are more than 2 feet away. Again, this forces the input gain level of the system to have to be set too high, and feedback will be likely to happen.

Solution: replace any dynamic vocal mics (such as the Shure SM58) with condenser microphones (our best choice is the Audio Technica ATM33a) if they are used for speech only. Ensure that singers are right up to their vocal microphones too, so that the gain can be kept low - just watch how pop singers almost eat their microphones.

We are available to answer any questions you may have - don´t forget that the sound quality in your church is as important to us as it is to you. As one of the leading suppliers of audio equipment exclusively to churches, we have seen pretty much everything, and we love to help!

Hope that your sound problems are improved by these changes.

Water damaged church audio equipment

2007-07-24T08:35:00.000+01:00

Now that the water from the floods is subsiding, we hope that your church has come through without much damage.

Unfortunately, a very few churches have sustained damage from water getting into their sound systems.

Our tips are as follows:

If there is any risk that your audio or video equipment is still wet, DO NOT switch it on

Microphones really don't like water - if they have been wet then please consider replacing

Mixers also don't cope well with water because of all the moving parts

Speakers are the final link in the chain, and if these get wet please consider replacing unless they are designed to cope with moisture (like our JBL Control range)

Finally - if you require a replacement quote for insurance, we are able to produce audio and video insurance quotes for churches, including replacement and repair of sound system, PA, amplifiers, CDs, microphones, cables and induction loops.

ChurchPA is comitted to getting your church back up and running as quickly as possible.

Congregational Pickup - is it worth it?

2007-07-16T14:34:00.000+01:00

We are looking into the possibility of extending microphone pick-up during congregation participation and require advice on how to install microphones that will pick up comment from the floor. Are you able to give us any advice?

Your requirement is one of the hardest things to do succesfully with a sound system, I'll try to explain why...

"Ambient" pickup in churches seems to be desirable because when the congregation is participating, you want to ensure that everyone can hear clearly.

However the problem comes because invariably the PA system is designed to amplify sound into the main body of the church - exactly where you want your ambient pickup to occur.

Normally your PA does not have feedback problems (if it does, SPEAK TO US - We are experts at helping you reduce church feedback problems). There is no feedback because microphones are used very close to the user. Therefore the pickup from around is minimised and it is simple to add a lot of amplification (gain) to the signal for the speakers.

However, if you try to pick up in a church from distance, however good the microphone is and whatever the type of microphone is, you will inevitably be picking up more of the ambience and hence by definition will pick up sound created by the sound system itself - a recipy for feedback problems (howling).

If the pickup is PURELY for the recording, then of course there is no problem and ambient pickup is simple BECAUSE you are not trying to put it through the sound system and amplify it. ChurchPA can easily advise you on pickup for recording in churches.

BUT- if you are trying to amplify your congregation, you need to decide to what lengths you wish to go to to achieve it. Our advice is to think twice...

Firstly and most simply you can provide an inexpensive handheld radio microphone that is held by those in the congregation when they speak. This way there is no feedback problem etc.

The other simple and easy solution is to ask people to stand at the lectern if they wish to speak. Simple, and most churches already have the technology for this one!

Next, it is possible to arrange for a "zone" in the church where those that wish to speak should stand - and with a suitable microphone and feedback destroyer (and careful microphone positioning) you can safely pickup from a mid sized area.

HOWEVER it really is NOT possible to pickup an entire congregation and amplify it back to that congregation. Feedback WILL happen.

Depending on your applications, it MAY be possible to come up with a suitable solution and we would definitely reccomend that you contact us to discuss your particular church. However, firstly we would recommend considering adding a handheld radio mic for those moments when the congregation needs to be heard!

Hope this helps, and don't forget that using our LiveHelp service, you can chat to ChurchPA in real time - you might even catch me answering!!

Tim.

Stereo or mono for church sound system installation

2007-06-04T17:20:00.000+01:00

Should a church have a mono or stereo sound reinforcement (public address) system. ChurchPA has the answer for your church or hall PA....

How is stereo sound used in real life?

Generally you send some or all of a particular source (i.e. microphone, guitar, drum) to a specific speaker so that you can recreate a "stereo sound image".

Where does stereo sound work well?

Actually it is perfect in the home when you are listening to your (aptly named) stereo system. By positioning yourself in a nice triangle with the speakers, you can get a really good representation of a realistic sound stage, with the guitar where it should be, the piano, each drum realistically spaced out and so on. The sound reaching your ears will be high quality and as if you are actually sitting in front of a band, choir or orchestra.

BUT what does this have to do with a public building like a church?

Not much, as it turns out. Assume for a moment that you have set up a really nice stereo mix, with the guitar panned to full right. Sounds great at the back of the hall where the stereo image is formed. But for the person right under that speaker, all they can hear is the guitar (TOO LOUD). And what about the person under the left hand speaker? They can only hear the guitar reflecting off the rear wall, if at all. To say this another way, the person under the left hand speaker cannot hear anything at all from the right hand speaker (due to psycho-acoustic masking)..

To say it another way:

In the case of amplifying live music and speech for public buildings, we strongly recommend that you go for a MONO system, where all you have to worry about is getting the relative volumes (sound levels) of each instrument correct, and then the sound will be correct for all listeners at all positions.

Stereo mixes only have relevance in the home, and possibly in your car. Mono audio for public buildings, churches and hall sound systems are a LOT less problematic.

Mic Rider Problem Solver!

2007-03-30T10:54:00.000+01:00

We now have stock of the fantastic new plug in DSP unit specifically for microphones! These units are the perfect accompaniment for speech microphones, and will make life SO MUCH EASIER for uses of sound systems.

This unit can be retrofitted onto most "wired" microphones, and gives you the folowing five powerful audio solutions:

FBX Feedback Exterminator - removes feedback to give you increased sound levels before problems
Automatic Gain Control - controls the sound level as you move closer and further from the mic
Proximity Effect Control - controls excessive bass as you get closer to the mic, and maintains a flat response at all distances from the mic
Plosive Control - controls loud pops and bursts from some sounds in speech
Infrared Gate - TURNS THE MIC ON AND OFF AUTOMATICALLY

This unit looks to be the ideal upgrade for all microphones, including singers microphones and lectern microphones, you just plug it in and benefit from the power of DSP digital signal processing on your audio.

It is as useful as having a professional sound engineer IN EVERY MICROPHONE.

The unit works with microphones which have a standard 3-pin XLR connector, and in systems which have a minimum of 17V phantom power (most modern mixers do!). It even passes through phantom power to your active microphones - clever!

You can see the pictures and information (and buy!) from our store...

http://www.churchpa.co.uk/store - search for "mic rider" to see the different versions available!

We know that this is the ONLY upgrade you need for your sound system this year!

PC Audio for churches

2007-03-07T15:01:00.000Z

Can you advise me the best/simplest way to get sound from our laptop computer to our sound system. We use the laptop in the centre of the church and the PA is at the back. We don't want to have cables trailing everywhere. Thanks!

Great question, and we have the perfect product just added to our webstore. This is a common problem, and so here goes...

We have a USB -> radio -> receiver system, which means that you DO NOT NEED any cables running from your PC audio to your PA system!

The USB stick plugs into your computer (laptop or desktop) and transmits the audio output of your PC via 2.4GHz radio to a small receiver. The receiver has phono outputs as well as a jack output, and therefore it is simple to connect it to any mixer system!

Hey presto - audio from your computer to your PA sound reinforcement system without wires.

It also crosses my mind that this unit could also be used in the home for that "wireless" sound sytsem, and could also be used to send audio from a PC to active (powered) speakers directly for a really simple to get working PC based sound system. Any budding DJ's out there in our community?

Check out the link here -> USB PC sound transmitter

SO, simple, great sounding audio from your PC is simple and easy!

Is my induction loop working

2007-02-22T08:55:00.000Z

A recent question:

There have been numerous reports regarding our loop not working. The question I have is, “how do we know it is working”? Obviously finding a hearing aid user and using them as a guinea pig is one method but is there a more scientific approach to be taken?? Are there any cost effective loop receivers available so we can check on a regular basis the loop?

The simple answer to your question is that you need a loop listener, which will enable you to listen in to the sound on the induction loop. We have two versions available, and the least expensive is available to purchase in the link below...

We have recently added a lower cost induction loop listener (receiver) to our range, and it is available from this link -> Loop Receiver - *Click Here*

We also have loop level meters, but find that these are less useful in the day-to-day running of a church.

As an added benefit of having a loop listener, you can hand the listener to those with poor hearing but with no hearing aid. Assuming that your loop IS working, you will be amazed at the clarity of sound that comes from an induction loop, and will want to use the loop listener all the time!

Installers Required

2006-05-17T10:17:00.000+01:00

Hello,

As part of our expansion through the UK, we are now urgently looking for installers to operate in the North of England and in the London region.

With great rates of pay, we know that this is an exciting job for people with the right qualifications to take on.

Preferably, the candidate will have experience with live audio, working in churches, good practical and problem solving skills. A head for heights is also essential.

All potential people are encouraged to email us on jobs@churchpa.co.uk

We look forward to speaking to you,

The ChurchPA Team

Sport Hall Sound System

2006-05-09T13:35:00.000+01:00

We worship in a large sports hall, and need a sound system for the worship group. Can you help, and what advice can you give?

Large sports halls such as this are notoriously difficult accoustic environment - echoes can be really bad, and it is quite hard to avoid introducing feedback (howling) sounds when introducing a sound system. With a hall like this, there are a couple of important points to bear in mind:

ALL microphones must be behind speakers or pointing away from them
Use directional microphones rather than "omni" microphones
Get the mic as close to the source as humanly possible, this greatly helps to reduce feedback as the gain on your mixer can be lower
If you can have an operator at the mixer, get them to "mute" unused channels such as the band when they are not playing. This will improve sound clarity in quiet sections
Get as much soft material into the room as possible. Can you run a carpet down the centre aisle? Can you put banners onto the walls?

You will also want to make sure that any equipment you select can be quickly and simply put up and taken down again. This might mean that you should spend a little more to make sure that everything is flight cased - it will pay off in the long term.

The other important consideration is to choose the right speakers for a sports hall. I actually feel that the ideal solution for the hall is to use the Carlsbro NlightN speakers. These use a completely different technology to conventional speakers, and are much less of a "point source". They really do help in reducing feedback problems - they look great too!

NlightN Flat Panel Speakers - Click Here

Since you are also trying to reproduce your band through the speakers, you should also consider the Slammer Bass Bin which is designed to run with the NlightN Speakers, and has all the internal amplification needed.

Slammer Bass Speaker - Click Here

With the NlightN/Slammer combination, you will be able to get a higher sound level without feedback.

Hope this helps!

Tim Ridgway.

Speakezee Portable PA - IN STOCK!

2006-05-02T14:26:00.000+01:00

We have just got stock in of the Carlsbro Speakezee Portable PA system

-------> Act now to reserve your Speakezee Portable PA

Click Here for More Speakezee Info

For those of you who have not seen or heard the Speakezee, let me tell you a little more... the speakezee is a convenient "all-in-one" sound system which you can just switch on!

The Speakezee is a battery/mains powered unit with built in 20 Watt speaker - perfect for meetings or even small outside gatherings. The battery is rechargeable, giving up to 3 hours of heavy use from a single charge.

The unit comes with not one but all three radio microphones styles - a handheld microphone, a tie clip lapel microphone and even a headset microphone! This allows you to select the most suitable microphone for your event, from a meeting to a party to a keep fit class. It is all included.

What is more, you will never have to take minutes at a meeting again, as the Speakezee comes with a built in tape player/recorder, so whatever your event is, the Speakezee is perfect!

Even more than this, the Speakezee comes with tone controls, and phono jack input ensuring that you can even plug in a CD or MP3 player to keep people happy before and after your event.
So, to recap, if you have or are planning any events, fetes or fairs, training days, meetings or weekends away, you really can't do better than take a Speakezee unit along with you.

You really are encouraged to buy now - they sell out very very quickly!

Available for £109.00 - Early booking essential !

You can see more details about the product on our webstore at the following address:

Click Here for More Speakezee Info

We really do find that the Speakezee is the most versatile and incredibly cost effective portable PA on the market. Stop shouting at meetings and spread the word with the Carlsbro Speakezee Portable PA.

Yours in Christ,

Tim Ridgway.

How to add speakers to a 100V PA system

2006-04-09T22:09:00.000+01:00

A recent question was very interesting to us, and will undoubtedly be useful for all churches who wish to extend their sound system...

We would like to add a couple of loudpseakers to our 100v system. At present we have 8 speakers in our system. What do I need to check before getting another couple of speakers, and how easy is it to 'patch' them in?

In a 100V system, you must not add more speakers than the amplifier will drive.

100V speakers have "taps" which are rated at different powers (such as 10W, 15W etc.). Amplifiers suitable for 100V are also rated with a maximum power, say 120W. You can effectively "daisy-chain" more speakers up to the maximum rating BUT we would not recommend going more than about 80% of the maximum to get the best sound, and to stay within tolerances of components.

Therefore to be able to determine how many speakers, and of which type, you can add, you must go to each speaker in your system and look on the back to see which "tap" has been selected. Add them all up. Then compare this to the rating of your power amplifier.
If there is spare capacity, it is simple to add in new speakers - simply mount them on the wall, run speaker cables either back to the main amplifier, or to a convenient speaker, and ensure that you connect "+" to "+" and "-" to "-". That is all there is to it.

One important questions to ask is this - what you are trying to achieve with the extra speakers?

Are you extending into another room, or trying to increase sound coverage, or to mask some other underlying problem in the sound system? Knowing the answer to this question will help in determining which speaker or speakers to install.

A very common issue we help with is churches with old column speakers which really do sound bad! Modern speakers can easily and greatly improve the sound, without resorting to any extra wiring.

We hope that this helps, and would point you in the direction of our "installed speaker" selection.
http://www.churchpa.co.uk/store/index.php?main_page=index&cPath=7_8

If you have any questions, or require further advice, please do not hesitate to contact us on the following email address (enquiries@churchpa.co.uk) , and we look forward to forming a strong relationship with you and your church.

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

Lapel Microphone "Booms"

2006-01-02T22:05:00.000Z

One of our ministers is rather animated and likes to look around lots while preaching. So his head is moving but his shoulders (and therefore the mic) are not. This causes him to get very quiet as he looks away from the mic and then suddenly get very loud as he looks "over" the mic. Any suggestions?

We suggest placing the lapel microphone as high as possible on the collar, so that the distance to the mouth is pretty much a constant. Placing the microphone too low down allows the mouth to move into and out of the "field of view" of the microphone, and too low down causes problems with picking up rumbling tummys (oh, and will increase the risk of feedback too!).

The reason for placing a lapel microphone as high as possible is to make it very hard for the user to get their mouth pointing directly at the microphone. High under the chin is a good place because unless you really bend your head forwards, your mouth is pretty much always the same distance from the microphone, wherever you turn your head. I challenge you to make your mouth point at your collar bone without forcing your head unnaturally downwards.

A lot of the sound of a lapel microphone is actually picked up from the throat, and they have (should have!) frequency responses designed to accommodate this. Additionally, as with all microphones, the closer the mic is to the source, the louder the signal picked up (obviously). This means that you can have the level set lower on the PA system, and thus reduce the risk of feedback howling. So, there are strong reasons for suggesting that a lapel mic should be high on the collar.

A point of interest is that news readers etc. on the TV can have their microphones lower down because their head is always facing forwards - there is no danger of them speaking to the floor.

You could also check to see if the "booming" is actually wind noise from speaking straight into the microphone somehow. The addition of a small foam wind/pop shield can help a little to reduce this.

One final tip is that by moving the microphone slightly to the side of the body (which happens on TV presenters as they clip onto their jacket lapel, or to the side on the collar of their T-shirt), gives a more natural sound which is less "nasal".

So, to sum up.... booming or sudden changes in volume only come when you change the distance from the microphone to the mouth. There may be a better place that you can find on your "animated" minister, but we really do find that higher up is best.

Tim Ridgway.

Tie mic feedback - help!

2005-12-21T11:23:00.000Z

We have problems with our lapel tie clip microphone giving feedback, what can we do about it? Also, would you recommend an EQ to eliminate these problems?

As a first port of call, we would probably NOT suggest adding a Graphic Equaliser to reduce feedback, although of course they can help!

There are a lot of things you can do without resortingEQ to reduce feedback.

Ensure the speakers are in front of all microphones at all times
Keep the "on stage" sound level down as low as possible - musicians to play quietly, keep foldback monitors low volume
Position the lapel microphone high up on the collar (and slightly to the side) so that it is very close to the sound source. This means that the microphone level in the mixer can be kept lower

You need to be very careful if heading down the EQ to reduce feedback route as it is possible to end up with a weak sound if you are not careful - really do think deeply about the actual causes of the feedback first.

However, if you really are having difficulties then a simple EQ can help to give you a little more headroom before feedback occurs. You need as fine frequency band control as possible - 31 is good - so that you don't alter frequencies which are not a problem. See....

Samson 31 Band Graphic Equaliser

Alternatively, a purpose built feedback destroyer can remove feedback without damaging the overall sound of your mix. See...

Samson Advanced Feedback Managment Unit

Finally, using a directional (cardioid) lapel microphone can also help to prevent feedback problems. The EW122G2 Sennheiser lapel microphone is a cardioid microphone, i.e. it has directional pickup. Don't forget that you have to position the microphone facing the right direction!

Sennheiser EW122G2 UHF radio microphone

Hope that this helps!

Tim

Competition Winner!

2005-12-20T11:59:00.000Z

Thank again to all who participated in our online web shop questionnaire. We are now shipping a large amount of audio equipment including microphones, mixers, speakers, cables and stands to churches across the UK (and even beyond!)

http://www.churchpa.co.uk/store

Thanks to all our loyal customers, and hello to all our new ones.

From Tim Curry, the winner of our microphone ...

"Thanks for sending the mic - I have attached a pic. Sorry its a bit cheesy! I think this is the first time I ve won something like this so I am dead pleased (as is our AV team who think the mic is lovely)"

Thanks to you too Tim, for entering our competition.

Bye for now,

Tim Ridgway.

We have a WINNER

2005-12-12T13:21:00.000Z

Hi All,

We have drawn a winner for our recent "Store Opening Competition Prize Draw" and the winner is -

Tim Curry from Wendover

Tim is the proud winner of a Shure PG57 Instrument Microphone.

Our thanks to everyone who entered the competition, and thank you all for the words of encouragement as we strive to serve the church community better.

Bye for now,

Tim.

100V Line vs. 8 ohm speakers

2005-12-05T12:04:00.000Z

Can you explain the difference (in non -technical terms) between 100V and 8 ohm speakers, and which we should choose. We require four speakers in our church.

Many older 100V speakers did not sound very good, and so lots of churches are changing them to modern speakers. However, new speakers, including the Control25 (8ohm) and Control25T (100V) speakers sound the same today. Therefore it is just the manner in which the signal is sent to the speaker which is different between the two systems. If you go for 8ohm speakers, you obviously connect them to the low impedance output from your amplifier and if 100V then connect to that output (note not all amplifiers have a 100V output).

The difference between the two systems comes in the wiring to the speakers. If you use low impedance speakers over long distances (greater than maybe ten metres) you need increasingly thicker copper in the speaker cable otherwise you get a lot of cable loss and distortion. So, for long distances 100V line is much better as you can pretty much use any old speaker cable.

Additionally, you mentioned that you wanted four speakers. With 100V line, you can literally connect all the + terminals together and all the - terminals together in any way the wiring happens to be. With 8 ohm speakers, you need to ensure that the impedance is above 4 ohms, which with four speakers involves wiring pairs in parallel and then connecting the pairs as a serial chain.

Most older churches are wired for 100V line systems as the speakers are both a long way from the amplifier and also the cable is not of thick copper. Therefore if you are updating your system it is highly likely that 100V speakers are suitable.

To say it again, with modern speakers, both 100V and low impedance speakers sound very similar.

Hope this helps,

Tim

Installation Fear

2005-11-28T12:49:00.000Z

We want to order an induction loop system but fear installation is going to be difficult as walls are white and smooth but have many pillars and indentations. Can the loop be installed at a height of 4 metres or alternatively on the floor?

The loop cable can go at any height, but should be kept away from running next to lighting mains cables (generally at ceiling height). Installing at 4 metres or at floor level is perfectly fine otherwise. We generally find that floor level is easiest, as long as the cable is not going to get trapped by chairs or pulled out by children! Installing on skirting board is very easy and safe, using hot-melt glue where appropriate.

Tim Ridgway.

Digital Hearing Aids

2005-11-10T09:57:00.000Z

Hello,

We have been asked again about the emergance of digital hearing aids, and their compatibility with induction loops.

Some very recent in-ear digital hearing aids do not have a "T" setting, and as such these device cannot pick up the signal from the induction loop at all. However these aids are often only for those with very mild hearing loss where the loop is not so essential anyway.

The vast majority of hearing aids still do have a "T" setting, so an induction loop is still of great benefit to many.

Tim

What information is needed for a loop

2005-11-08T17:07:00.000Z

Hi,

We get asked about hearing aid induction loops for churches, public buildings and halls all the time, and there are very few details that we need to be able to give you an on-the-spot price for your system. Having the answers to these questions to hand before calling us on 0845 4309486 saves time and will allow us to get a price to you as quickly as possible....

What are the dimensions of your building (front to back, left to right)?
What is the décor of the building - carpets/flooring, wall coverings, skirting board etc.?
What colour are the walls?
Details of any existing system, including makes and models - especially microphones and mixer (if you have one)?
Any digital photographs of the building? These can be incredibly useful if emailed to us!

If you need to discuss any of the above questions, please feel free to call us on 0845 4309486 (ask for Tim) and we would be glad to speak to you.

As you may know, an induction loop consists of a small cable run around the perimeter of the building - generally at low level. This typically goes right around the whole main meeting room, thus including the everyone at the meeting. There is also an induction loop amplifier that powers the loop. Users of the induction loop switch their hearing aid to the “T” position, and then can hear very clear sound from the loop.

See our full range of Loop Equipment in the ChurchPA online shop - Click Here

ChurchPA has the best prices for induction loop equipment online, and with our expertise we will be able to swiftly help you out.

Tim.

Web Shop Launch!

2005-11-03T22:14:00.000Z

We at ChurchPA are proud to have launched our online shop!

You can get to the store at www.ChurchPA.co.uk/store - check out the wide range of equipment, and don't forget that there is free shipping if your order is over £100. Of course our equipment is backed by a one year guarantee too!

Thanks, and we look forward to seeing you in the store!

Tim Ridgway.

Streaming Online Audio

2005-11-01T20:15:00.000Z

Hi all,

Just a quick one today. We have recently been selling quite a number of MP3 recorders to churches to enable them to record their services simply and easily, then to take away the recorder and copy off the audio onto their computer ready for copying onto CD. This is so simple to do today, that many older recording mechanisms are becoming obsolete.

MP3 Audio Recorder - Click Here

However, we heard today that one of our clients has gone one stage further, and is also posting the recordings onto the internet! What a great way to spread the word of God.

We had just one suggestion for this client to make the experience even easier for their users......

The old method they are using is to simply post the mp3 audio files as downloadable files on their web page. However, at 5Mb per sermon, it takes quite a long time before you can hear anything at all, even with a high speed broadband connection.

The new method we have suggested is to use Streaming Audio Techology which allows visitors to the site to listen to the recordings almost instantly.

Check out SoundStreamer, which we think is a fantastic application, and is very inexpensive. This application allows anyone to add streaming audio to their website, and it could be perfect for your church too!

Tim

Testing Loops

2005-09-19T08:59:00.000+01:00

Because you cannot listen to the sound on a loop without a hearing aid, it is difficult to really know that your induction loop is working without asking someone with an aid to inform you, which is often embarassing.

There are a number of devices which allow you to listen in on the loop as if you have a hearing aid, and others which give you the "field strength" of the loop. We recommend that you have a loop listener or field strength meter to ensure that you are putting the right sound onto the loop, and that you really are helping those in need.

ChurchPA supplies a good selection of loop equipment, and we would be delighted to discuss your needs.

Tim.

Induction Loop Amplifier v.s. Audio Amplifier

2005-09-19T08:54:00.000+01:00

Ocassionally in older churches, a "normal" audio amplifier is being used to drive an induction loop for the hard of hearing. This is the "way it was done" when purpose built induction loops did not exist. However, these days, it is NOT really acceptable to continue to do this....

We do not recommend using a standard audio amplifier to drive an induction loop as they really are not designed for this job. Having said this, they do work and are able to drive a loop, but it is very taxing for the amplifier to drive a low impedance loop and often the sound quality on the loop is much lower than that from an induction loop amplifier. You are also at risk of damaging the amplifier. Induction loop amplifiers are designed to drive the high current needed for a loop, they also have built in compressors to ensure that even if the source signal gets quieter or louder, the signal provided to loop users is of a consistent level, ensuring that they have a comfortable sound level in their hearing aid.

We supply a full range of induction loop amplifiers for all sizes of room, if you plan to replace your audio amplifier with a dedicated loop amplifier, we will need to know the dimensions of your room to be able to specify the correct amplifier.

Also check before re-using your existing loop cable that there is just a SINGLE turn around the room. To increase the impedance of an old loop they used to take several turns around the room (this was to prevent the audio amplifier overheating). It is not acceptable to have multiple turns with a modern loop amplifier.

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

Royal PA

2005-09-07T21:18:00.000+01:00

Hello everyone!

Just got back from the most amazing experience - providing a PA for Royalty! To be specific, we provided PA for the Gypsy Moth IV re-dedication on the Cutty Sark in London and Her Royal Highness Princess Anne was present for the dedication.

This was a real honour for us, and I think, the first time that our equipment has been checked by a sniffer dog. What an amazing world!

Well - we hope to post photographs soon.

Bye for now.

Tim

Audio and loop cables very close

2005-08-17T15:34:00.000+01:00

We're just re-doing our church sound system and I was wondering with the induction loop if any laying the loop next to our mic wiring loom (along the floor) will cause any problem hums, buzzes etc?

You can run loop cable next to audio microphone cables AS LONG AS your microphone cables are balanced cables and you are using balanced microphones or DI boxes at the source and balanced inputs on your mixer.

If there are any un-balanced cables or equipment involved you will no doubt have problems. You don't get a hum - instead you get feedback as the signal on the loop couples onto the microphone cable and is then re-amplified.

Remember - you can't put a loop near to an aluminium or metal suspended ceiling as this will stop it working. Also, in the UK it is against wiring regulations to install an induction loop closer than 60cm from mains wiring (including lighting) for long runs.

There is another post in our help pages which expands further on problems you can have with a loop, and why these are rarely actually a problem! Click Here

Hope this helps,

Tim.

FREE REPORT

2005-07-17T23:18:00.000+01:00

Hi All,

We at ChurchPA have just released our report "23 Ways to Improve the Sound in Your Church WITHOUT SPENDING ANY MONEY" - available exclusively from our webpage. Go to www.ChurchPA.co.uk and fill in the short form to get your hands on a copy!

We look forward to being able to help you in your church!

Tim.

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

ChurchPA's "Charity of the Year"

2005-07-03T15:56:00.000+01:00

The charity that ChurchPA will be supporting this year is ROPE - Relief for Opressed People Everywhere. This is a voluntary Christian charity, supporting the poor around the world.

Already we have supported a project teaching widows in the Gwembe district of Zambia the skills of “tie and dye”. This technique did not exist in this region until these women undertook the training. 90 women from around the region took part and will now be able to add to their income to help support their villages.

ChurchPA is proud to support this worthwhile charity. www.rope.org.uk

How much power?

2005-05-24T10:56:00.000+01:00

"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!

2005-05-20T11:01:00.000+01:00

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!

2005-05-18T17:05:00.000+01:00

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

2005-05-10T09:11:00.000+01:00

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 *****

Stopping Sound Reflections

2005-04-26T10:22:00.000+01:00

We were asked by a church if there was a way to reduce the reflections of sound off a back wall in their church caused from foldback monitors of their band. We of course suggest that it is best to reduce the sound level coming from the monitors, possibly by considering stand mounting monitors (see another of our posts) however, if the decor of the church allows it, you CAN reduce echos and reverberation with wall hangings and carpets on the floor etc.

Coverings on walls definitely reduces reflection. You need the heaviest possible material, and this should be hung a few inches away from the wall (leaving a gap behind) because then sound is absorbed as it goes from front to back, bounces on the wall and then is further absorbed as it bounces back again - double the attenuation. From an aesthetic point of view, it is difficult to treat walls in churches in this way - unless you are into the look of curtains - and as we have said before, reducing the foldback level is a quicker and simpler solution.

There are also devices such as "bass traps" which are designed to absorb sound. These look out of place in many churches, but the option exists and can work in some buildings.

So, firstly look to reducing the sound level from the foldback monitors, then add carpet where possible, finally consider adding wall hangings or sound traps at strategic points in the church.

We hope this helps.

Tim Ridgway.

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

Disability Discrimination Act - DDA Induction Loops

2005-04-25T14:09:00.000+01:00

Since about June of last year ChurchPA has seen a dramatic upturn in the number of churches requesting audio equipment, and in particular induction loop hearing aid systems. Many churches specifically wanted to beat the deadline of October, and many more wanted to have a loop in very soon afterwards. Having geared up to cope with this demand, we were also expecting that levels would return to normal towards the end of 2004, but this has not been the case. If anything, ChurchPA has been installing more audio systems and induction loops than ever in the first quarter of 2005, with no signs that it is slowing at all.

We are concerned that a large number of churches do not seem to know of the October deadline, or their need to try to comply with the Disability Discrimination Act. Other churches have been very caught up with the building access requirements, and have not thought about the requirements of the deaf.

Because of the large number of churches which still require hearing aid loop equipment, ChurchPA is continuing to grow this part of our business, and we anticipate that churches will be needing to have loop systems installed for at least the rest of 2005 before the majority have got the equipment they need.

Churches have very specific requirements when loop systems are installed, such as the need to have cabling invisibly installed. Of course most church buildings were not designed with the Disability Discrimination Act in mind, and it takes our expertise and experience to be able to successfully and safely install induction loop systems in the wide variety of buildings that we meet. We are also very mindful not to damage buildings when installing cables, so it very important to choose a skilled installer when selecting someone to put in a loop.

We feel that it is very important that churches comply with the DDA, and we are able to meet the audio and induction loop requirements of churches very swiftly. Many churches do not have any audio equipment at all, and ChurchPA has found that the requirement to have a loop installed has prompted many churches to assess their wider audio requirements, often leading them to put in discreet speakers, CD players and other audio equipment adding to their worship. These devices also aid those who are not hard of hearing.

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

***** Phone 0845 430 9486 *****

How can we improve our foldback monitoring?

2005-04-02T20:55:00.000+01:00

Many churches with bands/musicians make a real hash of foldback monitoring, yet it does not have to be this way, and a few simple changes can make life easier for the musicians, front of house sound and the congregation as a whole. This is the ChurchPA take on the situation....

Typically, bands in churches still go for the floor style "wedge" monitor to give foldback to the band members. However in most churches these actually cause a large problem. You see, with these speakers, the sound level has to be high for the musician to actually hear themselves clearly. Floor wedges are generally poorly placed due to floor space considerations - if you must use this kind of speaker, the speaker should point directly at the singer, and not have anything in the way, such as music on stands (or worse, word sheets actually on the monitor). To achieve this, the speaker often needs to be about one to two metres in front of the singer, yet they are normally placed right at the singers feet!!

Now, there is a physical law which can really help - thanks to God for a wonderful world. Sound level is proportional to distance SQUARED. What? Well if you halve the distance between a speaker and your ears, you can quarter the sound level from the speaker and still hear the same sound! Amazing! Had you ever wondered why PA systems are rated in the hundreds (to thousands!) of Watts, where headphones are rated at only 100mW? This is why! So..... We supply a discreet range of stand mounting monitor speakers, which are rated at 20W and by being placed at waist height can be a lot lot quieter. The speakers then give the musician a very local sound, and do not fill the church with problematical sound levels. The speakers are small, and if you have enough aux sends from your mixer, can be used to give just the right foldback to the musicians.

The next logical step from this is in-ear-monitoring. This is a small earpiece worn by the musician, so that they can hear exactly what they want. This is out of the cost range of most churches, but the option is there!!!!

A couple of extra monitoring tips -

Don't put the bass guitar through the monitors - the ambient sound from your PA should be enough for the bassist to hear themselves. Adding them to the monitor mix just reduces clarity in the speakers, and increases the "stage" sound level (a bad thing).
Get your musicians to play at a quieter level - this then means that the monitor speakers do not have to fight against them. The worst culprit is the.... drummer... we love them, but they cause so many problems! To allow your drummer to play at a normal level, and to stop using brushes (which they hate!), one can use a cost effective transparent acoustic drum screen, which means that all of the musicians around can still hear the drums, the drummer can play loudly but the sound is tamed.
After *every* song, get the mixing engineer to reduce the foldback just a fraction - the musicians will not notice, but the overall sound level on the stage is that much better off! Sneaky, but this really is a technique used by the top professionals!

So, next time you are being told by the singers that they cannot hear themselves, don't just rush for the volume control.

Bye for now.

Tim Ridgway.

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

***** Phone 0845 430 9486 *****

Induction Hearing Aid Loop Problems

2005-03-22T21:55:00.000Z

We get contacted a few times a year from people who are getting audio feedback problems because their hearing aid induction loop is interacting with a guitar - this is the solution....

You need to check a few things (in the order to check/rectify)

Are you using a "real" induction loop amplifier? Some churches have pressed an audio amplifier into service for the loop. This is not acceptable and causes odd peaks in the signal on the loop, which can cause these problems.

Is the loop level turned up too high? If the signal on the loop is too high, there is obviously a much stronger coupling between the loop and the guitar. So firstly check with a loop signal strength meter that the loop is at the right level.

Are you using very long unbalanced leads on the guitar? By this I mean is the guitar lead longer than about 5 metres? If so, you *must* use a lot shorter leads, as the coupling will be happening here.

Are you using unbalanced leads from the band area to your mixer? Again, any/every long unbalanced lead *will* couple with the loop. Use balanced cables and a DI box instead - this is the only real solution with long cable runs in conjunction with an induction loop.

We just said it, but will say it again - short unbalanced leads are essential with an induction loop.

Is the ground good in the guitar? It is essential that there is a good connection on the ground part of the guitar and this must also make a good connection to the lead. Additionally, there must be a good ground connection from the amp to the ground in the wall. Look into this if the above issues do not solve your problems, as it is slightly difficult to check (you can use a multimeter between mains socket GROUND and the metal work on the guitar - be careful and do not electrocute yourself!). If this is the problem, you need to shield the electronics in the guitar better, and maybe consider using a humbucking pickup. This can be done by a good guitar shop. This is a last ditch solution, and is 99.99% not necessary if the above solutions are used. You can also consider using a much higher quality guitar lead before resorting to any permanent changes in the guitar.

One final tip is to place the instrument amplifier as CLOSE to the loop cable as possible, as there is a dip in the field strength at the wire. Might just make some difference...

We hope that this helps you solve this problem, but if you wish to contact us, we would be happy to discuss your particular problem with you.

Tim.

Radio Microphones

2005-03-21T12:03:00.000Z

We have just come back from a church who were having problems with their radio microphones - one did not appear to be working. It turned out that adjusting the settings on the back of the microphone fixed the problem, but we know that many churches do not understand the settings on the back of their radio microphone receiver, so here goes for an explanation...

There are generally two controls on the back of a radio microphone receiver - the first is called Gain or Volume and the second called Mute or Squelch. What do they do???

The gain control adjusts the output level from the radio microphone receiver, so that it can match the input of the mixer/amplifier which it is driving. This can be very useful as you will see...

The Problem : we found that the church had the level controls on the mixer set to around 1.5 out of 10 for the radio microphone channels. This meant that there was very little room for adjustment when there was a loud speaker using the radio microphone - even the slightest touch turned off the channel or worse still made it far too loud!

The Solution : by reducing the output level from the receiver, using the Gain control, we were then able to turn up the level on the mixer input. Carefully, we were able to set a nice sound level where the mixer control was half way, i.e. 5 out of 10. This therefore meant that the operator had lots of upward and downward movement to compensate for different speakers.

The Mute control sets a threshold where the receiver decides that incoming radio signals must be rubbish, or interference. When the radio signal level is below this threshold, the receiver automatically mutes its output. This is great for ensuring that you do not pick up transmissions from local taxi firms, airports and such like. However it has a downside...

The Problem : it appeared that one of the radio microphone receivers was not working - or that the transmitter had stopped transmitting. Whichever, it seemed that there was no radio signal and therefore no audio coming from the microphone.

The Solution : on closer investigation, we found that the Mute control had been turned up to maximum. This meant that the radio microphone was muting out (removing) all signals, including the valid signal from the radio microphone transmitter. This gave the impression that the system was not working. By simply reducing the mute level we made the receiver "work" again. However, it is worth listening to the system with the transmitter off for a while to make sure that you don't then start picking up the local disco again.....

Well, thats it for this time.

Tim.

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

Our New Blogsite!

2005-03-20T21:52:00.000Z

Hi everyone!

Finally we have got our own blog! We plan to discuss new developments in audio equipment, general topics for audio in churches, and also to keep on top of the questions that people ask us about the sound in their church.

So, thanks for taking the time to read this blog, and we look forward to adding great content over time.

Tim.

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