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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Installed Sound/Contracting => Topic started by: Kyle Malenfant on January 08, 2014, 09:07:39 PM
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I have an opportunity to bid on an install at a local high school that wants to play music throughout the hallways for the 5 minutes between classes. The system would have to be loud enough to be heard over the commotion of high schoolers yelling at each other in hallways but not at the levels of what you'd hear at a high school dance.
The principle would like to keep things in perspective and asked use to place speakers approx ever 35 feet or so in the hallways. The corridors are in the shape of a U, and total 450' linear feet if you straightened out the hallway.
We have already installed video screens in multiple locations on each floor using coax cable carry HD-SDI with embedded audio. At each screen we used an AJA converter to output HDMI to each screen, and the converter allows us to break out the audio through stereo RCA out. It is from these outs that each floor will get its audio signal.
In the past I've set up plenty out audio installs using powered 15" speakers and separate amps and boxes. Would it be suggested that I look into a 70v system for each floor?
A recommendation on speakers to get over the noise of high schoolers would be helpful too. Thanks!
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I have an opportunity to bid on an install at a local high school that wants to play music throughout the hallways for the 5 minutes between classes. The system would have to be loud enough to be heard over the commotion of high schoolers yelling at each other in hallways but not at the levels of what you'd hear at a high school dance.
The principle would like to keep things in perspective and asked use to place speakers approx ever 35 feet or so in the hallways. The corridors are in the shape of a U, and total 450' linear feet if you straightened out the hallway.
We have already installed video screens in multiple locations on each floor using coax cable carry HD-SDI with embedded audio. At each screen we used an AJA converter to output HDMI to each screen, and the converter allows us to break out the audio through stereo RCA out. It is from these outs that each floor will get its audio signal.
In the past I've set up plenty out audio installs using powered 15" speakers and separate amps and boxes. Would it be suggested that I look into a 70v system for each floor?
A recommendation on speakers to get over the noise of high schoolers would be helpful too. Thanks!
Unless you have very high ceiling-and strong speakers-you will have some issues getting over the ambient levels.
They will have to be closer together.
Also consider this. If you add the music-the ambient level will go up-requiring more level to "get over them". And it will continue.
And what type of music would be played? Not all students like the same music. That can be a whole new can of worms.
Personally I think you will run into a number of problems/issues.
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Unless you have very high ceiling-and strong speakers-you will have some issues getting over the ambient levels.
They will have to be closer together.
Also consider this. If you add the music-the ambient level will go up-requiring more level to "get over them". And it will continue.
That's a really good point. Given the 10' high ceiling, I'd like to space the speakers closer to 20 ft apart, alternating on the left and right side of the hallway.
Increasing the volume of music over the commotion will, as you pointed out, only increase the amount of noise the kids generate. Certainly something to consider and monitor when the system is implemented.
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That's a really good point. Given the 10' high ceiling, I'd like to space the speakers closer to 20 ft apart, alternating on the left and right side of the hallway.
Increasing the volume of music over the commotion will, as you pointed out, only increase the amount of noise the kids generate. Certainly something to consider and monitor when the system is implemented.
It depends on how even you want the coverage/level. With a 10' ceiling you will need to space the speakers closer together than 20'.
There are all sorts of calculators from the manufacturers of ceiling speakers. Use them and find a number for a level/quality you want.
Yes it means a lot of speakers-but you need to ask the buyer if they want to do it right or live with the consequences of not (lower levels in between speakers).
Of course budget may be a driving force-but just something to consider.
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I would highly recommend a 70v system, and in particular I have been very happy with Atlas Sound FAP40T Speakers. We have installed hundreds of these and I have only had 1 bad one. As others have mentioned, for a perfect coverage, you would want to alternate sides of the hallway, but have them as close to 8' apart (45 degree dispersion, a person is 6' tall on average). But, since you are really just providing “ambient noise” and not listening to a presentation, I would think you could get away with installing them centered in the hall at 15’-20’ intervals, it just have a perfectly consistent volume as you walk through the hall. If you really wanted to get into it you could put each area on a seperate zone and use a Biamp AudiaFlex to route to different zones and even tie it in as an intercom with a phone interface that allows for paging and will duck the music. But even without zones, that can be done easily with some RDL products.
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I would highly recommend a 70v system, and in particular I have been very happy with Atlas Sound FAP40T Speakers. We have installed hundreds of these and I have only had 1 bad one. As others have mentioned, for a perfect coverage, you would want to alternate sides of the hallway, but have them as close to 8' apart (45 degree dispersion, a person is 6' tall on average). But, since you are really just providing “ambient noise” and not listening to a presentation, I would think you could get away with installing them centered in the hall at 15’-20’ intervals, it just have a perfectly consistent volume as you walk through the hall. If you really wanted to get into it you could put each area on a seperate zone and use a Biamp AudiaFlex to route to different zones and even tie it in as an intercom with a phone interface that allows for paging and will duck the music. But even without zones, that can be done easily with some RDL products.
On the note of 70v systems I'm a bit confused: the JBl control 23 is rated at 50 watts, yet only comes with a 5W tap for 70v wiring. How does the tap wattage compare to the rated speaker wattage?
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On the note of 70v systems I'm a bit confused: the JBl control 23 is rated at 50 watts, yet only comes with a 5W tap for 70v wiring. How does the tap wattage compare to the rated speaker wattage?
A larger wattage transformer would require a physically larger transformer-more size-higher price etc.
What the transformer rating simply means is that with a 70V input there would be a 5 watt into rated impedance output. SO about 6V if the speaker is 8 ohms.
If the input signal is higher than 70V more power/voltage would be going to the speaker-HOWEVER there will start to be more distortion/transformer saturation and so forth-so the sound quality would go down.
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On the note of 70v systems I'm a bit confused: the JBl control 23 is rated at 50 watts, yet only comes with a 5W tap for 70v wiring. How does the tap wattage compare to the rated speaker wattage?
You'd be surprised how loud a speaker will get with 5 watts. However, the Control 23t is only rated down to 100hz (-10db), so it really needs to be used with an external subwoofer, especially where younger people/modern music is involved. An improvement would be the Control 25t, which is rated down to 80hz and also has taps up to 30 watts. These are going to look kind of funky hanging in the hallway, plus their coverage pattern is less than ideal for a long narrow hallway. I would advise an in-ceiling speaker if at all possible. 6.5" or even 8" would be the size I would go for, unless you plan to use a few external subs.
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I have an opportunity to bid on an install at a local high school that wants to play music throughout the hallways for the 5 minutes between classes. The system would have to be loud enough to be heard over the commotion of high schoolers yelling at each other in hallways but not at the levels of what you'd hear at a high school dance.
The principle would like to keep things in perspective and asked use to place speakers approx ever 35 feet or so in the hallways. The corridors are in the shape of a U, and total 450' linear feet if you straightened out the hallway.
We have already installed video screens in multiple locations on each floor using coax cable carry HD-SDI with embedded audio. At each screen we used an AJA converter to output HDMI to each screen, and the converter allows us to break out the audio through stereo RCA out. It is from these outs that each floor will get its audio signal.
In the past I've set up plenty out audio installs using powered 15" speakers and separate amps and boxes. Would it be suggested that I look into a 70v system for each floor?
A recommendation on speakers to get over the noise of high schoolers would be helpful too. Thanks!
To be a bit of a curmudgeon, this sounds like are "Really Bad Fucking Idea."
Any system that gets loud enough to be heard over changing period kids will also be loud enough to mask any audible alarm or voice warning system. I submit for that reason alone this project be reconsidered.
It also sounds like a private school with more money than sense. Any public school principal that wanted this would be sacked for wasting funds that should go into the classroom. Is it really necessary to entertain children for 5 minutes?
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To be a bit of a curmudgeon, this sounds like are "Really Bad Fucking Idea."
Any system that gets loud enough to be heard over changing period kids will also be loud enough to mask any audible alarm or voice warning system. I submit for that reason alone this project be reconsidered.
It also sounds like a private school with more money than sense. Any public school principal that wanted this would be sacked for wasting funds that should go into the classroom. Is it really necessary to entertain children for 5 minutes?
The intention is to liven up the mood of the school, and help project it is as forward thinking and such. The music should be played at a volume loud enough to hear, but not to overpower the halls in any way.
That being said, right now I'm looking at the Control 24 CT..the 130 degree pattern is appealing.
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I wouldn't even waste money on a packaged speaker for something like this unless you have a lot of money. And the 24CT? what kind of low end levels do you think you will get? They are great for background/moderate foreground but not without subs and a crossover for what you want. I really think you are over thinking this. I would just go old school and use 8" speaker/transformer/ceiling baffle combos with a decent sized backbox. Space them every 12' right down the middle of the hallway. Use a quality speaker (actually look at the specs) and transformer and they will sound better than the 24CTs at a higher level and at a lower cost.
-Hal
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These things are literally made for mounting on the wall or from the ceiling in hallways. It is dual sided and aims a loudspeaker down the hallway in each direction.
Atlas Sound 510-4 (http://www.atlassound.com/Solutions/Products/387/510-4.html)
I would not put them up in the middle of the hallway or they would become a target for students to slap with their hands. I would mount them either from the ceiling or wall in the corner where the wall meets the ceiling.
The loudspeakers that go in these things are not made to make music sound good, they are made to make speech intelligible. You may want to install some 70V subwoofers along with these.
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These things are literally made for mounting on the wall or from the ceiling in hallways. It is dual sided and aims a loudspeaker down the hallway in each direction.
Atlas Sound 510-4 (http://www.atlassound.com/Solutions/Products/387/510-4.html)
I remember those from the sixties. ;D Don't think they would fit in with the "forward thinking" spec of this project.
-Hal
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To be a bit of a curmudgeon, this sounds like are "Really Bad Fucking Idea."
Any system that gets loud enough to be heard over changing period kids will also be loud enough to mask any audible alarm or voice warning system. I submit for that reason alone this project be reconsidered.
It also sounds like a private school with more money than sense. Any public school principal that wanted this would be sacked for wasting funds that should go into the classroom. Is it really necessary to entertain children for 5 minutes?
I agree with Tim on all points.
The fire alarm alone should stop you unless you build in a relay logic to drop audio when the alarm sounds. Fire alarm annunciators must get to a
Certain dB level over ambient noise. When you raise the ambient noise floor with music, then the alarm will have to be louder, however at some point you are just making peoples ears bleed so the code solution, at least in my AHJ, is that sound systems must stop passing audio at the moment the alarm sounds. We have this in every theater, bar, music venue, and yes school, in town. Some places have logic inputs to dsp modules, some have shunt trip breakers on the electrical supplies. To do otherwise would out you and your company at risk of liability if an alarm went off and people didn't evacuate because they couldn't 'hear it'. Even if they could eat it you have interfered with the code required level of function of the alarm and thus open yourself to a lot of liability.
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I agree with Tim on all points.
The fire alarm alone should stop you unless you build in a relay logic to drop audio when the alarm sounds. Fire alarm annunciators must get to a
Certain dB level over ambient noise. When you raise the ambient noise floor with music, then the alarm will have to be louder, however at some point you are just making peoples ears bleed so the code solution, at least in my AHJ, is that sound systems must stop passing audio at the moment the alarm sounds. We have this in every theater, bar, music venue, and yes school, in town. Some places have logic inputs to dsp modules, some have shunt trip breakers on the electrical supplies. To do otherwise would out you and your company at risk of liability if an alarm went off and people didn't evacuate because they couldn't 'hear it'. Even if they could eat it you have interfered with the code required level of function of the alarm and thus open yourself to a lot of liability.
This great Cailen, thanks. What interface do you recommend I look at to achieve the ducking of the music?
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Well - we use biamp products in most of our venues, but an audia with a logic box might be overkill. Some other people might have better suggestions.
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I remember those from the sixties. ;D Don't think they would fit in with the "forward thinking" spec of this project.
-Hal
Awww... come on Hal!
Those things are awesomely retro!
More importantly, they do exactly what the OP was looking for, and you can load them up with 70V loudspeakers.
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The intention is to liven up the mood of the school, and help project it is as forward thinking and such. The music should be played at a volume loud enough to hear, but not to overpower the halls in any way.
That being said, right now I'm looking at the Control 24 CT..the 130 degree pattern is appealing.
I will ask again-who chooses the music? Not everybody likes all kinds of music.
There is one style (and other "effects") that any song that even starts to have it is like nails on a chaulkboard to me.
THat would not "liven me up", but rather make me MAD that I had no choice but to hear it.
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I will ask again-who chooses the music? Not everybody likes all kinds of music.
There is one style (and other "effects") that any song that even starts to have it is like nails on a chaulkboard to me.
THat would not "liven me up", but rather make me MAD that I had no choice but to hear it.
Agreed. All due respect to your point, that for the principal and powers that be to manage.
All of the recommended points are great for me to consider. Addin in subwoofers is a great too..how would they be arrayed in such a narrow hallway? One per X amount of mid/highs?
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Agreed. All due respect to your point, that for the principal and powers that be to manage.
All of the recommended points are great for me to consider. Addin in subwoofers is a great too..how would they be arrayed in such a narrow hallway? One per X amount of mid/highs?
I'll pass personal judgment here. I think this is one of the stupidest ideas I've heard in ages, and I say that as a person who's degree program was in education. The is the kind of horse hockey that is usually reserved for football team..
When I work with schools, public and even many private ones, there ain't enough money to pay for batteries for wireless mics, let alone rent the RF. Here we're talking about playing music and doing some kind of lighting "happy dance" when what we want are the kids to get their books and supplies and their bodies into the class room. Does this school have money to shovel around? If so, they can stop this nonsense and send it USD #259, Wichita Kansas. Our students and teachers would be incredibly grateful to have new sheet music in our vocal music classes, new gel for the next play or musical, or muslin to build more flats.
Do they want moonbeams and rainbows installed, too? ;)
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I'll pass personal judgment here. I think this is one of the stupidest ideas I've heard in ages, and I say that as a person who's degree program was in education. The is the kind of horse hockey that is usually reserved for football team..
When I work with schools, public and even many private ones, there ain't enough money to pay for batteries for wireless mics, let alone rent the RF. Here we're talking about playing music and doing some kind of lighting "happy dance" when what we want are the kids to get their books and supplies and their bodies into the class room. Does this school have money to shovel around? If so, they can stop this nonsense and send it USD #259, Wichita Kansas. Our students and teachers would be incredibly grateful to have new sheet music in our vocal music classes, new gel for the next play or musical, or muslin to build more flats.
Do they want moonbeams and rainbows installed, too? ;)
Tim...
You have ascended to full curmudgeon-hood. Welcome to the club!!!
I'm in complete agreement. This is a prime example of "we don't have $$$ for what we need, but we have plenty for what we want"-ism.
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Well so am I and I work full time in a high school.
A couple of pep rally/ special occasions a year I will bring in a system and slam them with the music they like (and I hate) but no way I want that daily.
Sent from my DROID RAZR HD using Tapatalk
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My advice would be to install a good zoned Intercom system throughout the school so that it can be used for communication between classrooms and the office and to address the entire school. All schools in my area have these and they work great. Then if you want to play music. Hook it up and route it to the hallways like my school used to do. The kids don't care a bit about sound quality.
Also, to add on to what others are saying, not everyone likes the same kind of music and I was always mad or offended by some of the music played at my school. So I would discuss that with the people running the school before doing this. By the way, as a senior in high school, I can say a lot of high schoolers feel this way about music being played during school. Trust me it will bring more trouble than it's worth.
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Whether the project is a good or bad idea, the work needs to be done by someone so why not be in the running. I'm here simply asking for some input on the technical side, not the logical. That you to those who have offered useful advise. To those commenting on the silliness of the project, thank you as well as these are some points I will bring up to the principle in effort to help manage his expectations.
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Addin in subwoofers is a great too..how would they be arrayed in such a narrow hallway? One per X amount of mid/highs?
Most of the ceiling speaker companies make ceiling subs. some sound pretty good and others sound like somebody hitting a 5 gallon bucket.
What sort of budget does the school have for this disaster?
Have you ever done this sort of install? It does not sound like you have (by the type of questions being asked-sorry)-which adds another problem to the whole mess.
It is not just about "using speakers", but rather using them correctly and legally.
Are you certified and licensed to do low voltage install? Are you aware of the fire codes for wiring in a building and especially in a ceiling? If not-be ready for some heavy fines or lots of time and money redoing the system to meet code. Who is going to pay for that?
And what about the kids getting to class on time? What if they want to hang out in the halls and "jam"? And THEN start getting their stuff together to then start to go to class.
If the idea is to get them to move faster-then this is the wrong approach-except for the people who don't like the music and they will move faster just to attempt to get away from it.
Bad idea bad idea.
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Whether the project is a good or bad idea, the work needs to be done by someone so why not be in the running.
Primarily because the installer will forever take the heat for a hair-brained scheme when the myriad conflicts and short-comings manifest themselves. Are you really sure you want to take responsibility for this fuster-cluck???
thank you as well as these are some points I will bring up to the principle Principal in an effort to help manage his expectations.
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Whether the project is a good or bad idea, the work needs to be done by someone so why not be in the running. I'm here simply asking for some input on the technical side, not the logical. That you to those who have offered useful advise. To those commenting on the silliness of the project, thank you as well as these are some points I will bring up to the principle in effort to help manage his expectations.
Go to the school and look at the fire alarm control panel. Somewhere on it will be a sticker, label or a business card of the firm responsible for its installation, testing and maintenance. Call them, as they will doubtless be involved as this installation.
If the alarm and voice warning system is older, the change being proposed by the principal may well negate any 'grandfathering' that allows the existing system and necessitate a complete replacement of the alarm and voice warning systems. At the very least it may require changes that will impact the budget for the proposed project (like blow the budget).
I seldom try to talk a client out of handing me money, but this is on time I'd be really digging into what the client "needs" as opposed to what they say they want. And you're right, someone, somewhere will take their money (presuming the school board or committee doesn't stop this as the colossal waste of $$ that it is).
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Sounds like the goals and expectations need to be more clearly defind before any specific solutions should be discussed. How loud do they expect the music to be? What quality do they really expect or need? How much variation in level/coverage/response is acceptable? How might this system have to relate to other commmunication and/or life safety systems? What is the budget?
Then there are practical aspects like where the associated amplification and processing would be located, what cable paths exist and so on.
A simple example of the possible issues is that you could put speakers every 35' or so as requested but with 10' ceilings that then puts some students just 4'-5' from and directly under speakers with others close to 20' from and well off axis from the nearest speaker. That would likely result in significant variations in level, response, quality, etc., but whether that is accceptable depends on what they will accept.
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How might this system have to relate to other commmunication and/or life safety systems?
This is a very important point that people who are not in the business often forget.
Let's take an example. The time is inbetween classes with music blaring and kids in the halls making noise.
A shooter comes in the building (sadly happening to often these days).
The office tries to make an announcement/warning-but they are excited and forget to turn the music off. THe kids cannot hear the announcement because of the music. Some people die.
Now word gets out that the kids could not hear the announcement because of the "blaring music".
Whoever installed the system is going to be in some serious trouble.
The "music system" needs to be tied into the life safety system so that it is shut off during announcements-automatically.
So this also has to be taken into account when designing/pricing the system.
And whos responsibility is this? the new system designer or the life safety guys? It is both-because they have to work together to get it to work.
And who pays the life safety guys to modify their system or to hook into it? Just another expense that needs to be made clear ahead of time or somebody is going to be surprised when the bill comes due.
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This is a very important point that people who are not in the business often forget.
Let's take an example. The time is inbetween classes with music blaring and kids in the halls making noise.
A shooter comes in the building (sadly happening to often these days).
The office tries to make an announcement/warning-but they are excited and forget to turn the music off. THe kids cannot hear the announcement because of the music. Some people die.
Now word gets out that the kids could not hear the announcement because of the "blaring music".
Whoever installed the system is going to be in some serious trouble.
The "music system" needs to be tied into the life safety system so that it is shut off during announcements-automatically.
So this also has to be taken into account when designing/pricing the system.
And whos responsibility is this? the new system designer or the life safety guys? It is both-because they have to work together to get it to work.
And who pays the life safety guys to modify their system or to hook into it? Just another expense that needs to be made clear ahead of time or somebody is going to be surprised when the bill comes due.
When I was in high school in the early eighties, they used to play music between classes just like the OP is talking about.
They also used the already existing school intercom (Dukane I think) and they actually had those two-sided aluminum speaker "pods" mentioned earlier in this thread.
It sounded fine (when the ASB students in charge of it didn't overdrive the system's input with the Califone cassette player they were using :-)
Anyways my whole point is that it worked fine, was more than loud enough and actually had decent tone while never losing the announce functions or overrides that a whole-building school intercom was designed for.
So IMHO, just augment the existing "schoolhouse-approved" intercom life safety rig or install one from scratch if there isn't already one!
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I have an opportunity to bid on an install at a local high school that wants to play music throughout the hallways for the 5 minutes between classes. The system would have to be loud enough to be heard over the commotion of high schoolers yelling at each other in hallways but not at the levels of what you'd hear at a high school dance.
In our school PA/intercom business, this is a fairly standard feature that the administrators call "March to Music". It is integrated with the IC/PA/clock/bells system. The music is piped through hallway announcement speakers, timed between the bells. The idea is that when the student hear music, they'd better be marching along to next class. When music stops, you'd better be there.
We usually have AP announcement speakers in the hallway ceilings; our standard is Atlas SD72W cut into ceiling tiles, max 20 feet apart. Not real hi-fi or hi powered, but clear and loud enough. You might be surprised how loud speakers tapped at 1/2 watt can be.
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In our school PA/intercom business, this is a fairly standard feature that the administrators call "March to Music". It is integrated with the IC/PA/clock/bells system. The music is piped through hallway announcement speakers, timed between the bells. The idea is that when the student hear music, they'd better be marching along to next class. When music stops, you'd better be there.
We usually have AP announcement speakers in the hallway ceilings; our standard is Atlas SD72W cut into ceiling tiles, max 20 feet apart. Not real hi-fi or hi powered, but clear and loud enough. You might be surprised how loud speakers tapped at 1/2 watt can be.
This is exactly the effect the school is looking to achieve. What I'm having a hard time understanding is what does a 1/2 watt tap sound like in reference to a standard small PA system i.e. jackie or JBL powered speakers (SRM450, PRX etc.). I certainly understand these are apples and oranges as far as speakers go, but looking for a base point to reference off of.
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This is exactly the effect the school is looking to achieve. What I'm having a hard time understanding is what does a 1/2 watt tap sound like in reference to a standard small PA system i.e. jackie or JBL powered speakers (SRM450, PRX etc.). I certainly understand these are apples and oranges as far as speakers go, but looking for a base point to reference off of.
Bring an SRM350 to the school and play music at max volume in a hallway and I think you'll find out pretty quick that it is not the benchmark you should be referencing.
Jason
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Specific mfr. make systems that will do just what you want, maybe not the fidelity you are after.
Rauland, Dukane, Simplex, Telecor, Valcom etc. and all have disconnects to fire alarm and emergency call, etc. built in. Those would be the only systems we would spec out for a project like this. Most are through dedicated distributors in the area, other than Valcom....look at these first. Yes they are costly, but also serve for main PA, background music, voice announcements, warning systems, clock and bell, all in one package.
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This is exactly the effect the school is looking to achieve. What I'm having a hard time understanding is what does a 1/2 watt tap sound like in reference to a standard small PA system i.e. jackie or JBL powered speakers (SRM450, PRX etc.). I certainly understand these are apples and oranges as far as speakers go, but looking for a base point to reference off of.
It's the overall performance that matters rather than just the tap value and different speakers can provide significantly different levels and response with the same tap value. Then you also have to go beyond the speaker itself to address frequency based losses for listeners off-axis, losses from the distance of listeners from the speakers, possible signal processing that may be applied, etc.
Quite frankly, I'd guess they really just want some decent quality music at a reasonable level with quite a bit of variation in the level and response being acceptable. I think the focus on sound quality, the music being clearly heard over the ambient levels, comparisons to foreground music systems, etc. may be causing you to make it more complicated than it really is.
One concern I have is that is you try to get full range music at sufficient level to be heard over the ambient noise everywhere in the hallways then not only will you have very high levels in some areas but the music levels might be to where they could potentially interfere with life safety and emergency systems. That is why it may be required to automatically mute the music during any emergencies or life safety announcements.