Gymnatorium Upgrades

[ChasB]

Hello,

I'm a band director at a small public middle school in Iowa, and am also involved in the technical side of our theatrical productions (fall play and spring musical). Though, I am primarily a musician, I also have a strong background in building speakers and feel very comfortable digging into the workings of our PA.

A month or so ago, my principal came to me with complaints about our PA from the community. He made a presentation to our school board about making upgrades this year, and they have agreed that we do need an upgrade. Unfortunately, they haven't given me a budget to work with yet (I'm going to guestimate under the $15,000 mark, but they may give me more), and I highly doubt any acoustical treatments will be possible since it will still have to function as a gym.

I do have something of a wishlist, but no specific components picked out yet. We are looking to upgrade everything. Right now, we have an archaic 12 channel powered yamaha mixer, a pair of mismatched speakers, and a pair of equally archaic monitors. I'm looking for (at the very least) a 24 channel mixer (unpowered), a power amp, and new speakers. I imagine we don't need a ridiculous amount of power, as the 200-300 watt (RMS) output of our powered mixer is more than enough to fill the space. I would like to build a setup that has a relatively flat frequency response, provides even coverage for the audience (linear array?), and is fairly easy for me to train other staff members. I am not in the least bit afraid to build the speakers, as we have all necessary tools and a maintenance guy that is very helpful.

Any suggestions are greatly appreciated.

 

[jkowtko]

I do sound for a local middle school's music concerts here in California, have been able to get it to sound pretty good with minimal equipment. We have pull out bleachers that seat ~500, and acoustic panel treatments on the other three walls. High vaulted ceiling. The building is ~5 yrs old.

If you have something remotely similar feel free to PM me, send pics and we can compare notes.

Thanks. John

 

[AlexDonkle]

I highly doubt any acoustical treatments will be possible since it will still have to function as a gym.

I'm not understanding this statement, we've added acoustical treatment to a lot of gyms largelybecause they were gyms. One case the reverb was so bad, the basketball players couldn't understand what the coaches were shouting, so we did an analysis and covered the ceiling and some of the walls in acoustical panels. Cheapest and most common arrangement is Tectum acoustical panels mounted on the walls (they are impact resistant, designed to take a lot of abuse), and MBI lapendary banners mounted between the roof perlins (depending on the building structure). Downside is that you'd likely need a contractor to install them, involving a lift, which would get expensive and involving hiring an architect to put together bid documents at most schools.

My opinion, even with upgraded loudspeakers and other components (most likely bigger speakers mounted on tripods), you'd still be likely to get noise complaints if the acoustics aren't addressed.

 

[BillConnerFASTC]

Hello,

A month or so ago, my principal came to me with complaints about our PA from the community.

It bothers me that educated people blame the sound system when the problem is the room. As one well respected acoustical consultant once said in the midst of planning a very large and expensive gymnatorium - maybe arenatorium - "Mozart in a gym is just offensive."

 

[jkowtko]

Our gym has a cinder block shell, but there are two major forms of acoustical treatment that no doubt help significantly:

* a six foot high 2" thick black pad around the three walls that the bleachers are not on, for student safety
* large (6-8' square) acoustic baffle panels placed around the walls above the padding

The bleachers are on the fourth wall and break up the sound well enough when pulled out from the wall.

And then there are the hundreds of parents, filling the bleachers and sitting and standing around the sides of the room. People make great acoustic baffles

I place two SRM450 speakers on stands on the gym floor about 8-10' out from the front corners of the bleachers, and a center fill placed just in front of the conductor's podium on a 2 foot high stand. The main speakers are pointing at the center of the back wall of the bleachers.

I've been using this setup for six years now for spring and winter concerts, and it sounds pretty good. I notice no echo and very little reverb ... although I'm sure there is some, but it's very well controlled.

 

[rwhealey]

Hello,

I'm a band director at a small public middle school in Iowa, and am also involved in the technical side of our theatrical productions (fall play and spring musical). Though, I am primarily a musician, I also have a strong background in building speakers and feel very comfortable digging into the workings of our PA.

A month or so ago, my principal came to me with complaints about our PA from the community. He made a presentation to our school board about making upgrades this year, and they have agreed that we do need an upgrade. Unfortunately, they haven't given me a budget to work with yet (I'm going to guestimate under the $15,000 mark, but they may give me more), and I highly doubt any acoustical treatments will be possible since it will still have to function as a gym.

As others have mentioned there are plenty of options for acoustic treatment for a gym. The two most common are probably Tectum, a hard wood like product that is impact resistant (http://www.tectum.com/project-photos-interior-walls.html) and lapendary banners, which are soft vinyl covered ceiling panels that take a hit from a ball since they hang loosely (http://mbiproducts.com/products/lapendary/). The nicest sound system in a room with poor acoustics will still sound bad. There are thing you can do with a sound system to help avoid poor acoustic problems, but it is usually cheaper and easier to fix the acoustics in the first place.

Depending on the size of your room, I think your $15,00 is a little low for a high quality performance sound system if you don't plan on re-using any parts.

I do have something of a wishlist, but no specific components picked out yet. We are looking to upgrade everything. Right now, we have an archaic 12 channel powered yamaha mixer, a pair of mismatched speakers, and a pair of equally archaic monitors. I'm looking for (at the very least) a 24 channel mixer (unpowered), a power amp, and new speakers. I imagine we don't need a ridiculous amount of power, as the 200-300 watt (RMS) output of our powered mixer is more than enough to fill the space. I would like to build a setup that has a relatively flat frequency response, provides even coverage for the audience (linear array?), and is fairly easy for me to train other staff members. I am not in the least bit afraid to build the speakers, as we have all necessary tools and a maintenance guy that is very helpful.

Any suggestions are greatly appreciated.

Your comment about building speakers is a bit of a red flag for a few reasons. You won't be able to build something that can be certified to fly yourself. The cost of having a structural engineer design and a licensed contractor build a cage for non-flying speaker will greatly exceed the cost of buying a speaker designed to fly. Furthermore, despite claims out there on the internet that you are being ripped off by large commercial speaker manufacturers, there is a reason speaker manufacturers charge what they do for their speakers. Even if you manage to design a speaker that sounds better than a pre-made one, which is a tall order, the cost of materials and labor (your time and the maintenance guy's time are valuable) greatly exceeds the cost of buying a commercially available speaker. There are some pros out there who build their own speakers for fun, but unless you are Clair Global you aren't building them for profit.

My advice is that ask for design funds from the school board to bring in a professional. They can work with you on budgeting and system planning and produce design documents you can put out to bid.

 

[FMEng]

I think rwhealey summed it up pretty well. The cost and complexity of building a sound system that will provide adequate intelligibility is proportional to how bad the acoustics are. Gyms and large, traditional churches are among the worst. Without a well engineered design, you stand a good chance of throwing most of your money away without actually making any improvement in people being able to understand the spoken word. Find a consultant to do the design without any interest in selling you an installation. Then hire a contractor to implement the design to the consultant's specifications.

Plan on spending most of your installation budget on acoustical treatment, rigging, speakers, amps, and processing. The "front end" of the system, like mics, mixers, cables, monitor speakers, etc. can always be improved and added to later. None of the "front end" stuff matters if the sound doesn't get from the speaker to the audience or if the reverberation destroys intelligibility.

 

[jkowtko]

I think you guys are overthinking it. Don't hang speakers from a gym ceiling or you'll get nothing but reflections. Place them on stands six feet off the ground and close to the audience, and it will sound fine. Cover them with speaker cover fabric to make them look nice if you like. Aside from very high-end line arrays, I have never heard ceiling mounted speakers that sounded very good. Since your budget isn't $250k, I think $15k will just get you into a lot of trouble. Try spending $2-3k on a club gig setup and I bet you'll be happy with your bang for the buck.

 

[lwinters630]

I put a sound craft si expression in a gym and some sure sm58. The compression on the sound craft was a major improvement. Added some portable Mackie pointed at the bleachers so I could reduce feedback from the ceiling mains into the mic. It's still a gym now they can understand what is said or sung. 7 - 10k

 

[FMEng]

There is only one way to improve intelligibility: Improve the ratio of direct sound to reflected or reverberant sound. You can do that a few ways.

1. Reduce the reflectivity of surfaces by adding absorption. This is easy to do with high frequencies and hard to do at low frequencies.
2. Increase the directivity of the speakers so less sound hits reflective surfaces. Again, this is hard to do as frequencies get lower.
3. Improve the evenness of coverage across the audience.
4. Get the speakers closer to the listeners.

That last one doesn't work in many situations. The first three take expertise to accomplish.

I disagree that ceiling speakers don't work. It is harder to make them work, because it takes the right type of speaker, the right quantity, put in the right place. (See numbers 2 and 3 above.) Just recently, it is getting easier to put the right speakers in highly reverberant spaces, because the speaker manufacturers are making speakers that can control patterns like nothing that came before. The catch is the right speakers cost more, so contractors install bid winning systems that don't work. Consequently, many examples in school gyms are very poor. Anyone can make loud noise in a space, but it takes an expert to provide intelligible speech.

I'm not an acoustician, so I will stop playing one on TV.

 

[Robert]

I spec'd a small line array system into a gym and had satisfactory results. This was a change from the 4 3-way delayed box speakers someone else suggested. I guess this would fall into the category of directed sound. During rehearsals it is too bright, but as mentioned add about 500 portable sound baffles (people) and you get good coverage and less splatter. No special sound treatment done, though I suggested hanging about 250 sound blankets in the steel work. They were too expensive. We avoided digital sound consoles as no one was there to run it on a continual basis. I did have a the install company put in a DSP and sweep the room. Working very well 6 years later.

 

[AlexDonkle]

I think you guys are overthinking it. Don't hang speakers from a gym ceiling or you'll get nothing but reflections. Place them on stands six feet off the ground and close to the audience, and it will sound fine. Cover them with speaker cover fabric to make them look nice if you like. Aside from very high-end line arrays, I have never heard ceiling mounted speakers that sounded very good. Since your budget isn't $250k, I think $15k will just get you into a lot of trouble. Try spending $2-3k on a club gig setup and I bet you'll be happy with your bang for the buck.

In my experience, if the school principal is actually receiving complaints from the community about the sound, it's almost guaranteed to be an intelligibility problem. New speakers might sound a bit better with more bass, but they don't fix problems like that. Acoustical treatment on the other hand, make any speakers used in the space sound better and clearer to the audience.

 

[BillConnerFASTC]

In my experience, if the school principal is actually receiving complaints from the community about the sound, it's almost guaranteed to be an intelligibility problem. New speakers might sound a bit better with more bass, but they don't fix problems like that. Acoustical treatment on the other hand, make any speakers used in the space sound better and clearer to the audience.

I agree. I've observed acoustic consultants demonstrate this to the owner/user group convincingly a number of times. Plenty of volume, just not understandable. Shaping and absorption. Quieting the HVAC is also often an ingredient to improving acoustics. Only a/v contractors seem to think it can be solved with only their gear.

 

[ChasB]

Thanks for all the input! I guess when I was writing the original post, I was so concentrated on treatments for the floor and low hanging baffles from the ceiling that I forgot to take into account wall treatments and other things. I talked to my principal again about some options for acoustic treatments, and we have decided to bring in a consultant from Des Moines. Our space isn't as big as you think it is (it's not even a regulation size basketball court), and on average, we have about 200 people come to our performances. As it sits right now, there aren't any speakers flying in the middle of the gym. Our speakers are wall mounted on either side of the stage.

 

[rwhealey]

I think you guys are overthinking it. Don't hang speakers from a gym ceiling or you'll get nothing but reflections. Place them on stands six feet off the ground and close to the audience, and it will sound fine. Cover them with speaker cover fabric to make them look nice if you like. Aside from very high-end line arrays, I have never heard ceiling mounted speakers that sounded very good. Since your budget isn't $250k, I think $15k will just get you into a lot of trouble. Try spending $2-3k on a club gig setup and I bet you'll be happy with your bang for the buck.

Highly directional speakers flown from the ceiling will allow you to have even coverage and keep the sound off the walls. Speakers on stands six feet in front of the audience are nice for portable situations because they're easy to set up, but are poor from a coverage standpoint because you will be much louder in the front than in the back. Unless you tilt the speakers down, a good portion of the sound will go right over the audience and hit the back wall.

$3k won't even buy you a 24 channel console and a case (http://www.fullcompass.com/product/...ign=googleps&gclid=CI-Qrue50sICFQuQaQod6IQAeg).

 

[Timothy A. Samuelson]

It bothers me that educated people blame the sound system when the problem is the room. As one well respected acoustical consultant once said in the midst of planning a very large and expensive gymnatorium - maybe arenatorium - "Mozart in a gym is just offensive."

THANK YOU!!!

I have gotten non-stop complaints about the sound system. We're running a PM5-D with Community speakers. Yeah, I've got some bad cables that sometimes get used unintentionally, but the system is incredible. It's the carpet, cloth seats, millions of wall panels, and ceiling clouds that are making the space so muffled. (I should mention that our "theater" was originally a mega-church. I still have a working baptistry)

 

[teqniqal]

Another reason to bring-in an experienced acoustics and sound system design consultant is that the two systems have to work together. Finding a functional and budgetary balance between HVAC noise reduction, room acoustics, and new sound equipment is a delicate balancing act. All the acoustical treatments and sound systems in the world won't help if the HVAC is too noisy and drowns-out the subtleties and nuances of the performer's voices and/or instruments; and acoustical treatments must find a balance between absorption and diffusion so that the performers can have a sense of their own presence in the space (overly dead rooms are difficult to perform in). Reducing the noise floor of the room is also vital to achieving useable recordings - microphones don't discriminate between voices, instruments and HVAC noise.

Theatre imposes different operational requirements on a sound system than does making general announcements for a sports event or playing in a rock band, so hiring someone that 'gets' theatre can go a long way towards having a theatre-friendly sound system.

In a theatre or music setting, particularly with inexperienced performers and sound operators, it always seems that the sound system is run right on the ragged edge of going into feedback, so you might see if you can get a demonstration of the Tectonic Audio Labs PL-12 speakers. They work well in spaces that don't have optimum acoustics, and their resistance to feedback is amazing. This allows you to place the speakers down low, flanking the performance area, and further create the acoustic illusion that the sound is coming from the performers and not from a disembodied source as when the reinforced sound is coming from above the performance area.

Being afraid of using a digital sound mixing console can further impede your success at presenting good quality audio to the audience. Digital mixers that allow you to individually adjust the signal delay of each microphone can add presence to the performance when the microphones that are upstage of the speakers are adjusted to deliver sound to the speaker system in-sync with the sound emanating from the source. This reduces the 'hollowness' frequently heard in many presentations. These features, like any other aspect of a mixer, can be ignored or misused by the operator, so settling for mediocre sound just to meet the least skilled operator's needs is a recipe for a lack-luster presentation.

 

[FMEng]

so you might see if you can get a demonstration of the Tectonic Audio Labs PL-12 speakers. They work well in spaces that don't have optimum acoustics, and their resistance to feedback is amazing.

I get very nervous when I see speaker manufacturers making claims that defy physics. It's one thing to claim they have a flat panel speaker that exhibits wide dispersion and linear reproduction. It sounds like snake oil when they make claims like the speaker "has very little interaction with the room." We know that wide, uncontrolled dispersion is the worst possible thing in a highly reverberant space, yet they seem to claim otherwise. Sorry, I'll wait until reputable acoustical engineers start employing these things with documented results.

 

[jkowtko]

Here are some photos of our gym setup, showing the black wall padding and the high mounted acoustic panels. Sorry these are not great photots ... I didn't take any myself and had to ask the videographer to grab a couple of frames from some of his footage (which focuses entirely on the musicians and not the sound setup .

You can see my center fill -- Anchor AN-1000x on a small homemade stand. On the leftside image you can also see another Anchor speaker as piano monitor for the choir.

What you cannot see, unfortunately, are my mains ... Mackie SRM450s mounted on tripod stands. They are positioned on the same line as the center speaker, even with the sides of the bleachers.

What you also cannot see is the vaulted ceiling (dome roof). I don't remember if the ceiling has acoustic treatment or not.

 

[Builtkarr]

I get very nervous when I see speaker manufacturers making claims that defy physics. It's one thing to claim they have a flat panel speaker that exhibits wide dispersion and linear reproduction. It sounds like snake oil when they make claims like the speaker "has very little interaction with the room." We know that wide, uncontrolled dispersion is the worst possible thing in a highly reverberant space, yet they seem to claim otherwise. Sorry, I'll wait until reputable acoustical engineers start employing these things with documented results.

So, I'm currently the TD of a high school theater program and in the process to transition to a new high school theater as TD. Before my start date at new theater the current theater chair has lined up a demo with Tectonic Audio Labs to show off their flat speaker panel due to sound issues in their space that I will be present for. The FOH speakers are hanging from the ceiling at the proscenium upstage of the stage extension. Obviously this is the reason for the problematic sound issues as when the stage extension is in, the action is being played downstage of the speakers with body or handheld mics causing feedback.

I've looked at Tectonic's website. http://www.tectonicaudiolabs.com I have watched a number of their informational videos and read some of their articles and it looks pretty amazing how they can reduce / cancel feedback. So obviously if this new high school has the money and can invest in this speaker system I'm all for it. Sound is my weakest discipline and if these speakers work the way they claim to it will save me a serious headache while I'm trying to learn new ropes as well as equipment all while keeping the season going from a technical standpoint without constantly fighting feedback.

I've searched for "tectonic", "DML" and this is the only thread that came up. So I wanted to see if we could expand the thread a bit on this topic. I'm wondering two things.

1. Are there any of you out there who have witnessed demo's of these speakers or who have them in systems you currently work in or have worked in? If so, are they as good as they claim to be? FMEng is skeptical... Is there a negative side to going with these speakers that may not be well known? For the demo I will be a witness to are there any specific questions I should be asking, or specific situations I should ask the tectonic people to put their speakers in to see results? Keep in mind I have not worked in this venue yet, just toured it and saw a small band perform for a few minutes.

2. It seems to me that moving the existing speakers downstage to the front of the stage extension should solve the feedback problem and in theory should be way cheaper than going with an entirely new system. Getting new stuff is great, especially in high school which is typically drastically underfunded and of course I'll take them if they tell me we are going that way, but just saying....

Any feedback would be appreciated.