Dear all,
First of all please let me tell you that I am a complete newb on this matters, i worked as DJ in my youth but never got too much into the technical aspect of the business. Years passed and now I do work in a totally different area which is the hospitality (hotel business to be more exact). One of our hotels is experiencing an expansion and the owner asked me to design the audio system for a new mini-ballroom that they're going to use as conference/speech room.
Naive as I am, accepted and now I am quite in trouble, hehe...
Will jump straight away to the basics. The room is a carpeted floor, gypsum wall/ceiling area of 11m width, 24m length and 4m high. I have used some program to calculate what kind of (ceiling) speakers should I install to have a decent sound distribution, and i ended up with 10 units of 8" speakers evenly installed through the area.
The cable im using for these is just generic (don't ask, i have budget limitations and some material stock that i had to use), and every of the speakers leads to the sound control cabin, which is equipped with a TOA ZA2120 amplifier and a Yamaha MC82CX mixing table.
We have two possible locations for the stage, which are represented in the pic below. Since the use is going to be simply speeches or conferences, i just passed one cable directly from each of the locations till the sound control cabin.
Now the problem is, i have two batches of 5 cables (divided in L/R groups) and I don't really know how to attach them to the amp, should all them just go in the rear panel squished as one or should i use some kind of box to combine them first? What is the standard procedure for this case?
Detail of the sound control cabin below:
Also, I passed just one cable that is going to end in a Jack-in outlet in every stage position just to install a fixed stand microphone for the MC, the rest of mics will go wireless, the point is... I know it can be done (way) better, what's your advice, audio wizards?
One more thing, presenting to the owners the plan in Sketchup looks not right from my point of view, what program should i use to present this kind of design in a professional way?
A BUNCH of thanks in advance, I don't mind being flamed as long as I can learn, so fire away!
Thanks again,
Eth.
First of all please let me tell you that I am a complete newb on this matters, i worked as DJ in my youth but never got too much into the technical aspect of the business. Years passed and now I do work in a totally different area which is the hospitality (hotel business to be more exact). One of our hotels is experiencing an expansion and the owner asked me to design the audio system for a new mini-ballroom that they're going to use as conference/speech room.
Naive as I am, accepted and now I am quite in trouble, hehe...
Will jump straight away to the basics. The room is a carpeted floor, gypsum wall/ceiling area of 11m width, 24m length and 4m high. I have used some program to calculate what kind of (ceiling) speakers should I install to have a decent sound distribution, and i ended up with 10 units of 8" speakers evenly installed through the area.
An externally hosted image should be here but it was not working when we last tested it.
The cable im using for these is just generic (don't ask, i have budget limitations and some material stock that i had to use), and every of the speakers leads to the sound control cabin, which is equipped with a TOA ZA2120 amplifier and a Yamaha MC82CX mixing table.
We have two possible locations for the stage, which are represented in the pic below. Since the use is going to be simply speeches or conferences, i just passed one cable directly from each of the locations till the sound control cabin.
An externally hosted image should be here but it was not working when we last tested it.
Now the problem is, i have two batches of 5 cables (divided in L/R groups) and I don't really know how to attach them to the amp, should all them just go in the rear panel squished as one or should i use some kind of box to combine them first? What is the standard procedure for this case?
Detail of the sound control cabin below:
An externally hosted image should be here but it was not working when we last tested it.
Also, I passed just one cable that is going to end in a Jack-in outlet in every stage position just to install a fixed stand microphone for the MC, the rest of mics will go wireless, the point is... I know it can be done (way) better, what's your advice, audio wizards?
One more thing, presenting to the owners the plan in Sketchup looks not right from my point of view, what program should i use to present this kind of design in a professional way?
A BUNCH of thanks in advance, I don't mind being flamed as long as I can learn, so fire away!
Thanks again,
Eth.
I mentioned is 4 meters high, mickey 
I used the TOA program for ceiling speaker calculation, the results were using 8 units, I added 2 just in case.
Link to the program: TOA Speaker System Design Software
Eth.
I used the TOA program for ceiling speaker calculation, the results were using 8 units, I added 2 just in case.
Link to the program: TOA Speaker System Design Software
Eth.
Your basic plan looks good, and I don't see any problems with the Sketch-up, it looks nice.
A few points:
Ive worked in 100s of ballrooms that have ceiling speakers. Generally they don't work well, so I always brought my own. I can remember only 1 exception to this over many years. So don't expect too much. It will work, if you plan correctly.
A few points:
- I can't find that amp on the TOA site. Got a link? Is it a 70V amp?
- With speaker cable runs like this, you should go to a 70V system.
- Forget stereo, run it all mono or use zones if you want
- If you can arrange a switch or control to turn off the speakers over the stage, you should. It will sound better and help avoid feedback.
- Don't expect a distributed speaker system like this to sound great, they rarely do. If done right you should get enough vocal intelligibility to make it worth your while.
- One mic line at each position is probably OK, but if you have the budget, do a few more. Remember, a lot of presenters will want sound from their laptop on stage.
Ive worked in 100s of ballrooms that have ceiling speakers. Generally they don't work well, so I always brought my own. I can remember only 1 exception to this over many years. So don't expect too much. It will work, if you plan correctly.
If you are using 100V (or 70V if you are in the USA sphere of influence) speakers, then it is a good rule of thumb to set the speaker tappings to give a total load on the amplifier to no more than 80% of its rated power. This way you will have enough headroom in the amp to allow you to increase the individual power settings on some of the speakers if it is found that the SPL is not high enough in some parts of the building.
Thanks a lot for the answers.
@Pano
Regarding the "stereo" thing, yeah we could call them zones as well, as the speakers are grouped in two areas as well. Yeah stereo definition didn't make too much sense after all...
I separated a bit the speakers from the stages position on purpose, hope its enough!
Yeah, I know is not gonna be a miracle of sound quality, but at least and as you say Pano, I hope at least to make it useful for people to understand the speeches
Regarding putting more inputs in the stage positions, now is too late since the walling is closed already and would be messy... couldn't I fix that with a stage box?
@Ouroboros
The amplifier is a 120V one, IIRC, the speakers are 7.2V so total power needed would be 72V, I applied some margin and got a 120V. (Is what you guys mean, right?)
Thanks a lot again, I really appreciate your input.
Eth.
@Pano
Regarding the "stereo" thing, yeah we could call them zones as well, as the speakers are grouped in two areas as well. Yeah stereo definition didn't make too much sense after all...
I separated a bit the speakers from the stages position on purpose, hope its enough!
Yeah, I know is not gonna be a miracle of sound quality, but at least and as you say Pano, I hope at least to make it useful for people to understand the speeches
Regarding putting more inputs in the stage positions, now is too late since the walling is closed already and would be messy... couldn't I fix that with a stage box?
@Ouroboros
The amplifier is a 120V one, IIRC, the speakers are 7.2V so total power needed would be 72V, I applied some margin and got a 120V. (Is what you guys mean, right?)
Thanks a lot again, I really appreciate your input.
Eth.
Hi Ether. No, not the mains. The voltage of the speakers. See this:
Constant voltage speaker system - Wikipedia, the free encyclopedia
Important for systems like this. It's the best way to do it.
I don't know what you mean by a "stage box". Is this a multichannel snake you plan to run back to the mixer?
Constant voltage speaker system - Wikipedia, the free encyclopedia
Important for systems like this. It's the best way to do it.
I don't know what you mean by a "stage box". Is this a multichannel snake you plan to run back to the mixer?
I agree with Pano, unless you have some need to send individual signals to each speaker, forget the wires out to each one. Study that "constant voltage" speaker distribution article. In the USA, that tends to be "70.7 volt" distribution. Most commercial PA amplifiers include a 70.7v output or some other CV output. Then all speakers are in parallel running from the same pair of wires. At each speaker will be a small matching transformer with adjustable taps. They are not expensive. You could run all the speakers together, or you could connect them in groups - "zones" - so the room can be divided in use.
CV speaker distribution will sound OK, especially for this sort of application. I used to install them for jukebox systems in restaurants and such, and no one complained it wasn't hifi enough.
The suggestion about turning off the speaker over the stage was good. Or just don't put one over the stages in the first place.
CV transformers have power taps. The signal is sent down the wires, and a ceiling speaker will usually have something like taps for 0.5w, 1w, 2w, 5w, 10w. Or whatever. In a bar or restaurant, for example, if there is a speaker over the waitress station, they would tap it lower. In other words if all the ceiling speakers were set at 5 watts, the one over the waitress station would be set at 1 watt. That way for a given loudness that one area would be less loud, so they can hear their orders.
CV speaker distribution will sound OK, especially for this sort of application. I used to install them for jukebox systems in restaurants and such, and no one complained it wasn't hifi enough.
The suggestion about turning off the speaker over the stage was good. Or just don't put one over the stages in the first place.
CV transformers have power taps. The signal is sent down the wires, and a ceiling speaker will usually have something like taps for 0.5w, 1w, 2w, 5w, 10w. Or whatever. In a bar or restaurant, for example, if there is a speaker over the waitress station, they would tap it lower. In other words if all the ceiling speakers were set at 5 watts, the one over the waitress station would be set at 1 watt. That way for a given loudness that one area would be less loud, so they can hear their orders.
Forget the stereo idea.
The system needs to be set up as a commercial 70.7 volt mono speaker system.
Forget the mix console as it isn't needed. A simple TOA A912-II will work fine.
It has 8 channels and you can use different plug in modules. Line or mic as
needed. It can be designed as simple or complex as you would like.
What I mentioned is simple. The system can and should be more complex to include
an EQ such a a DFR22, multiple delays, multiple amps just to get going here. Two mic's
per area. If computer is used then a transformer will be needed in order to get rid of
the 60Hz noise from the computer. Also a direct box or two needs to be considered.
Also provisions for line level input into the system from each area. If the area is going
to be divided into smaller zones then additional thought must be given to making each
area a stand alone system able to combine thru a automatic switching system of
some type.
If you want to email me I will design a complete system. I do this for a living.
Tell me what you want to do and I will design a fail proof turn key system.
Quote:
I've worked in 100s of ballrooms that have ceiling speakers. Generally they don't work well, so I always brought my own. I can remember only 1 exception to this over many years. So don't expect too much. It will work, if you plan correctly.
You haven't been in one that I have designed or worked on.
The system needs to be set up as a commercial 70.7 volt mono speaker system.
Forget the mix console as it isn't needed. A simple TOA A912-II will work fine.
It has 8 channels and you can use different plug in modules. Line or mic as
needed. It can be designed as simple or complex as you would like.
What I mentioned is simple. The system can and should be more complex to include
an EQ such a a DFR22, multiple delays, multiple amps just to get going here. Two mic's
per area. If computer is used then a transformer will be needed in order to get rid of
the 60Hz noise from the computer. Also a direct box or two needs to be considered.
Also provisions for line level input into the system from each area. If the area is going
to be divided into smaller zones then additional thought must be given to making each
area a stand alone system able to combine thru a automatic switching system of
some type.
If you want to email me I will design a complete system. I do this for a living.
Tell me what you want to do and I will design a fail proof turn key system.
Quote:
I've worked in 100s of ballrooms that have ceiling speakers. Generally they don't work well, so I always brought my own. I can remember only 1 exception to this over many years. So don't expect too much. It will work, if you plan correctly.
You haven't been in one that I have designed or worked on.
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You never know.
But I'll trust you. The only really good ceiling speaker system I remember was in a hotel in Columbia S.C. And it was a Bose system. Yeah, Bose. Sounded great and worked flawlessly. I didn't bother to unpack my speakers. That was a house sound system done right. We need more of those.Ether, you should jump at the chance to have 6BG6GA design your system. Having someone who does it professionally help out will save you a lot of headaches and mistakes.
Ditto on the direct boxes (DI). You'll need one or two to get sound from a laptop to the stage. And don't forget a CD player at in the sound booth, tho those are becoming less used.
Pano,
As you know you cannot get away with hooking a computer straight to a direct box because 90 times out of 100 you will end up with hum. The solution is to use a S2M or something similar with the direct box for a noise free source. Use a lot of them in churches with the flock now utilizing computers to save the sinners. As mentioned the ballroom/ meeting room systems suffer the same problems. everyone is under the illusion that you can plug anything into a system and it will work flawlessly well it usually doesn't.
I'm willing to help in the dilemma Ether has. I will admit right now I an curious as to your answer if its sarcasm.
I must admit that I didn't read the thread before answering. It sounds like the system is wired and speakers are purchased? If so too bad. No offense but I always cringe when someone not in the field decides to engineer something because to be blunt they don't have the knowledge or experience to come up with something workable.
As you know you cannot get away with hooking a computer straight to a direct box because 90 times out of 100 you will end up with hum. The solution is to use a S2M or something similar with the direct box for a noise free source. Use a lot of them in churches with the flock now utilizing computers to save the sinners. As mentioned the ballroom/ meeting room systems suffer the same problems. everyone is under the illusion that you can plug anything into a system and it will work flawlessly well it usually doesn't.
I'm willing to help in the dilemma Ether has. I will admit right now I an curious as to your answer if its sarcasm.
I must admit that I didn't read the thread before answering. It sounds like the system is wired and speakers are purchased? If so too bad. No offense but I always cringe when someone not in the field decides to engineer something because to be blunt they don't have the knowledge or experience to come up with something workable.
Unless you have a good budget to purchase the necessary equipment I would suggest that you settle on either A or B as the stage setting. For a proper system that will focus on intelligibility there is a need for multiple delays and multiple amplifiers. The goal being the point source. The further away from the stage setting the more the delay so that one thinks he or she is hearing from the front. This is the proper way to do it for a convention system.
As mentioned additional switching equipment would be needed in order to run this in the "B" mode also and to switch back and forth as the situation requires. With the stage on the side of the room the speaker lines will become longer left to right and you will still need the delays but at different settings. Number of delays will be less and amplification channels less and delay times will change.
In the ballroom mode where dancing and music would be played I would set it up as one zone I will call it with no delay lines.
Ballroom no delays
"A" system stage at end will require more delays and more amplifier channels.
"B" system on the short side of the room will require less delay' and less channels of amplification.
As mentioned there is equipment out there that can be set up and programed to switch to the "A" mode and have the correct delays and amplification channels. When switched to "B" it will change to that mode. When set to ball room the mode changes again. It can be done this way which is the easiest and it can also be done manually believe it or not.
Speakers... You mention 10?
When I walk a room (finished system)with pink noise on and my sound level meter in my hand I want to see less than a 2db change. Ten speaker wouldn't work for me. I want to see a nice overlap in coverage. Put your calculations in a program called ease and see what the response will be. I can usually look at a room and tell you the number and type/name of the speaker for good coverage.
Bottom line is this..... Its not as simple as throwing in some speakers to make noise and calling it good. The system must be designed considering the usage of the system. Now days Hotels make up a bunch of income by having a lavish extremely good working system that doubles as a convention system with multiple focal points and as a classy ball room system. It takes money to do so but the pay off is its booked 98-100% of the time making money for the Hotel. Sorry but what you have figured it doomed to be a so so system. In other words it kind works sometimes you can understand a speaker and when used for music you can almost enjoy it.
As mentioned additional switching equipment would be needed in order to run this in the "B" mode also and to switch back and forth as the situation requires. With the stage on the side of the room the speaker lines will become longer left to right and you will still need the delays but at different settings. Number of delays will be less and amplification channels less and delay times will change.
In the ballroom mode where dancing and music would be played I would set it up as one zone I will call it with no delay lines.
Ballroom no delays
"A" system stage at end will require more delays and more amplifier channels.
"B" system on the short side of the room will require less delay' and less channels of amplification.
As mentioned there is equipment out there that can be set up and programed to switch to the "A" mode and have the correct delays and amplification channels. When switched to "B" it will change to that mode. When set to ball room the mode changes again. It can be done this way which is the easiest and it can also be done manually believe it or not.
Speakers... You mention 10?
When I walk a room (finished system)with pink noise on and my sound level meter in my hand I want to see less than a 2db change. Ten speaker wouldn't work for me. I want to see a nice overlap in coverage. Put your calculations in a program called ease and see what the response will be. I can usually look at a room and tell you the number and type/name of the speaker for good coverage.
Bottom line is this..... Its not as simple as throwing in some speakers to make noise and calling it good. The system must be designed considering the usage of the system. Now days Hotels make up a bunch of income by having a lavish extremely good working system that doubles as a convention system with multiple focal points and as a classy ball room system. It takes money to do so but the pay off is its booked 98-100% of the time making money for the Hotel. Sorry but what you have figured it doomed to be a so so system. In other words it kind works sometimes you can understand a speaker and when used for music you can almost enjoy it.
If I figured meters to feet correctly I come up with a ceiling height of roughly 13ft. A length of 78feet and a width of 36feet.
The program roughly figured a speaker placement of 12ft on center. In other words a speaker at 12feet and at 24ft going across on the 36ft width and a speaker at roughly 12,24,36,48,and 60 ft going down the long way.
The program is banking on the height to help with a broader coverage.
Well, its junk to be blunt. It a basic commercial speaker calculator program designed to provide a basic coverage.
I would be willing to guess that the coverage will vary by 5-6db walking the floor.
You will have to increase the speaker count to provide better coverage.
The program roughly figured a speaker placement of 12ft on center. In other words a speaker at 12feet and at 24ft going across on the 36ft width and a speaker at roughly 12,24,36,48,and 60 ft going down the long way.
The program is banking on the height to help with a broader coverage.
Well, its junk to be blunt. It a basic commercial speaker calculator program designed to provide a basic coverage.
I would be willing to guess that the coverage will vary by 5-6db walking the floor.
You will have to increase the speaker count to provide better coverage.
Well I guess it depends on the DI. I always send laptop to the console via a direct box, no hum problems. Will have to look at what box I use. It's active, I think.
I was just poking fun. You set me up for that one.
Can't say I've ever done a show in Hawkeye-land. Never even been there. But from what I know, stuff is usually done right in that part of the world, so no worries.Pano,
To be honest here I don't know if I want to waste anymore of my time. I have the experience in years and systems. I have been all over the country working on someone else's crap. I have zero time for most DJ's because of their attitude and lack of knowledge and experience. A typical DJ system is throw something up on a couple of speaker stands apply mega power to some very inefficient speakers eq the hell out of it by ear and call it good and call yourself a professional.
From a moderator like yourself I expected more than a sarcastic reply and attitude. I'm not a Hawkeye fan nor do I consider this to be Hawkeye land and maybe we do things better here. In N.C. I only have a football stadium that I've worked on so I cannot comment as to the back woods equipment used in the hill country. I can tell you this much...the system under consideration is an abortion in the making. You guys go ahead and have at it.
To be honest here I don't know if I want to waste anymore of my time. I have the experience in years and systems. I have been all over the country working on someone else's crap. I have zero time for most DJ's because of their attitude and lack of knowledge and experience. A typical DJ system is throw something up on a couple of speaker stands apply mega power to some very inefficient speakers eq the hell out of it by ear and call it good and call yourself a professional.
From a moderator like yourself I expected more than a sarcastic reply and attitude. I'm not a Hawkeye fan nor do I consider this to be Hawkeye land and maybe we do things better here. In N.C. I only have a football stadium that I've worked on so I cannot comment as to the back woods equipment used in the hill country. I can tell you this much...the system under consideration is an abortion in the making. You guys go ahead and have at it.
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6:
Unfortunately you are right in many points, but there is no need to get cheesed off. I have designed and managed hundreds of installs. From small boardrooms to convention centers and a 50k+ seat stadium. The only places I learnd to stay away from are churches, as each congregation has an expert (worked at Radio Shack for 6 weeks).
And yes, the "system" under discussion here will be a dissaster and Ether may have to leave town for a while! E
Unfortunately you are right in many points, but there is no need to get cheesed off. I have designed and managed hundreds of installs. From small boardrooms to convention centers and a 50k+ seat stadium. The only places I learnd to stay away from are churches, as each congregation has an expert (worked at Radio Shack for 6 weeks).
And yes, the "system" under discussion here will be a dissaster and Ether may have to leave town for a while! E
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