Our system in the church is roughly 25 years old and is going to be replaced by a modern system. One question we have is about the current speakers.
There are 6 main speakers in the church and a total of 25 speakers across the building. They are all 100v and connected to 4 (parallel connected) cables leaving the power amplifier (the current amplifier has 1 connection).
In the new situation we want to fine tune volume per speaker, delay and maybe other characteristics(?).
Assuming we replace all the hardware but not the speakers. Can we achieve that requirements with the current cables and speakers?
There are 6 main speakers in the church and a total of 25 speakers across the building. They are all 100v and connected to 4 (parallel connected) cables leaving the power amplifier (the current amplifier has 1 connection).
In the new situation we want to fine tune volume per speaker, delay and maybe other characteristics(?).
Assuming we replace all the hardware but not the speakers. Can we achieve that requirements with the current cables and speakers?
If You want to control "per speaker" You have to feed each speaker with it's own cable, unless You put some sort of a networked amp on each speaker, but even this way You would have to provide power & network or wireless connection to the speakers.
If You just want to control level, there are in-wall level controls.
It is pointless to control delay. I mean You can adjust the delay of each speaker for a specific place (middle of the church for ex), but if You stay at the entrance or at the altar other speakers will sound delayed regarding to the nearest one.
What You can do is adjust the volume so that at the minimum required volume You don't hear the speakers on the other side.
If You don't want to hear delays, place big PA speakers at the altar, so that the sound comes from only one source an then use the others at low volume as "surround" speakers.
If You just want to control level, there are in-wall level controls.
It is pointless to control delay. I mean You can adjust the delay of each speaker for a specific place (middle of the church for ex), but if You stay at the entrance or at the altar other speakers will sound delayed regarding to the nearest one.
What You can do is adjust the volume so that at the minimum required volume You don't hear the speakers on the other side.
If You don't want to hear delays, place big PA speakers at the altar, so that the sound comes from only one source an then use the others at low volume as "surround" speakers.
Exactly. You parallel all the speakers. In larger installs you make zones (the kitchen the bathrooms the lounge ) and give each zone ( all the speakers in that zone) an amp out. You ballance the individual speakers by the transformer taps, often inside the cans ( some have dials on the face) and adjust the zones by amp. Delays per speaker means a dsp per speaker. Never done. But different zones usually have dsp these days. There is off the shelf hardware that does this including multi channel amps. Hard to make recomendations without more details.
Almost forgot, once the speaker watts are set by the transformer taps, add them all up and thats how much power youll need from your amp, and make sure your amp is a 100v system amp, not the usual 8ohm kind.
Almost forgot, once the speaker watts are set by the transformer taps, add them all up and thats how much power youll need from your amp, and make sure your amp is a 100v system amp, not the usual 8ohm kind.
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It points out for me that we could/should drop the delay requirement. Delays are not a problem at the moment, but I was thinking of it. I'd like to make things perfect and have to find a balance between price and good enough.
The hint of volume control by using different taps on the speakers is also very helpful.
When I tear down these replies: Replacing the current speakers for active ones does not outweigh the extra costs and cable-work.
It now boils down to asking ourselves if we need control per zone/room.
Thanks all for the replies!
The hint of volume control by using different taps on the speakers is also very helpful.
When I tear down these replies: Replacing the current speakers for active ones does not outweigh the extra costs and cable-work.
It now boils down to asking ourselves if we need control per zone/room.
Thanks all for the replies!
it might be worth it to PAY a professional sound contractor to assess your system and make recommendations.
If you have say a speaker in a crying room or a classroom off to teh side, you can tap it down on a transformer, but for additional control, you can add an L-pad between transformer adn speaker right in that room. Now you can dial it down to nothing if you like.
If you have say a speaker in a crying room or a classroom off to teh side, you can tap it down on a transformer, but for additional control, you can add an L-pad between transformer adn speaker right in that room. Now you can dial it down to nothing if you like.
On my experience, you can often increase voice intelligibility and lower the noise floor of the decades old 100V systems in a very inexpensive way, provided that the current system has been installed correctly. Replace the microphone preamplifier with a new one with a compressor function, and check individually each one of the old speakers to be sure that it is still working properly with no rattling or other malfunctions at high (but realistic) volumes. If the power amplifier does seems weak or it does make hum/white noise, replace it. You can also try replacing the filter capacitors, if the amplifier is a good quality one. The next step would be to add acoustic treatment, but this will be a lot more expensive and requires specialized measurement tools and skills.
Not a lot of DIYA folks will understand the need for speaker delays. A real professional system with delays will be expensive and require distributed amplifiers. I found this:
https://www.rolls.com/doc/manuals/manual_HRD342.pdf
and
Digital Delay
In any case I would recommend separate small amplifiers. Small amplifiers are not more expensive than speaker attenuators and far less problematic. You can buy computer speakers c/w amplifier for $30. You can use the existing 100V line where appropriate and adapt/attenuate it for input to delays and local amplifiers, or simply convert the entire system to a balanced line level. There is also the possibility to use FM and Bluetooth and wifi. Many Churches have used FM to service hard-of-hearing customers. That could mean that you just need a radio in remote rooms.
https://www.rolls.com/doc/manuals/manual_HRD342.pdf
and
Digital Delay
In any case I would recommend separate small amplifiers. Small amplifiers are not more expensive than speaker attenuators and far less problematic. You can buy computer speakers c/w amplifier for $30. You can use the existing 100V line where appropriate and adapt/attenuate it for input to delays and local amplifiers, or simply convert the entire system to a balanced line level. There is also the possibility to use FM and Bluetooth and wifi. Many Churches have used FM to service hard-of-hearing customers. That could mean that you just need a radio in remote rooms.
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Don't forget to delay the Preacher lips....now that You have delayed the speakers.
It's pointless to install delays. The front row of speakers will always be delayed from the last row if You attend at the last row.
Which one are You delaying ? The front or the last row ?
You can indeed calibrate delay to all speakers, but only for a sweet spot. Where ? Front ? Middle ? last row ? Where do You want to attend ?
Ok now You are calibrated.... but all other attenders not.
It's pointless to install delays. The front row of speakers will always be delayed from the last row if You attend at the last row.
Which one are You delaying ? The front or the last row ?
You can indeed calibrate delay to all speakers, but only for a sweet spot. Where ? Front ? Middle ? last row ? Where do You want to attend ?
Ok now You are calibrated.... but all other attenders not.
Indoors, delay speakers achieve two objectives:
- More consistent front-to-back SPL
- More consistent direct-to-reflected sound across the audience.
Delays are applied to the speakers towards the rear of the room so that they can combine coherently with the wavefront from the speakers near the front.
With that in place, the delays and relative levels can be tuned to alter the apparent acoustic source, but we're getting towards psychoacoustics there.
There are downsides, of course, but they're generally outweighed by the advantages, particularly for spoken word applications.
Chris
- More consistent front-to-back SPL
- More consistent direct-to-reflected sound across the audience.
Delays are applied to the speakers towards the rear of the room so that they can combine coherently with the wavefront from the speakers near the front.
With that in place, the delays and relative levels can be tuned to alter the apparent acoustic source, but we're getting towards psychoacoustics there.
There are downsides, of course, but they're generally outweighed by the advantages, particularly for spoken word applications.
Chris
PA system design is about articulation. The plague of sound systems is the reverberant field where echoes out of time from the source make speech unintelligible, and boosting the sound level does not help. Speaker delays should be slightly more than the acoustic delay so that the apparent source remains the front of house, even though the delayed speakers are louder. Delayed speakers should be directional and oriented away form the front of house. Theater acoustics are important and the rear of the theater should be a sound absorbent as possible.
https://www.amazon.com/Sound-System-Engineering-4e-Fourth/dp/0240818466
https://www.amazon.com/Sound-System-Engineering-4e-Fourth/dp/0240818466
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