# Sound in a gym



## MisterTim (May 10, 2010)

I know this is always a no-win situation, but what suggestions do you guys have for running rock bands in gymnasiums? 

I've made use of wrestling and gymnastics mats behind the drummer as well as the drum shield in front, also using the mats behind the whole band in general to keep the monitor reflections off the back wall down. 

I'll be in Virginia running a band in a gym for 12 performances over a week, so I'd like to go a little more prepared to handle it this year than last year.


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## DuckJordan (May 10, 2010)

cheap chunks of carpet placed under the monitors and drum set will be a great way to reduce noise from floor to ceiling that can cause problems.


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## rwhealey (May 10, 2010)

I've been told that carpet really isn't as good of a sound absorber as you might think.

Any way to use IEMs?


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## MisterTim (May 10, 2010)

rwhealey said:


> I've been told that carpet really isn't as good of a sound absorber as you might think.
> 
> Any way to use IEMs?



No IEMs. think low-budget. Carpet good, IEM bad for budget. 

But even without monitors, the sound is so boomy out of the mains.


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## museav (May 10, 2010)

Some general concepts. Try to keep the sound aimed at the audience and minimize the sound hitting the walls, ceiling, etc. This may mean trying to get the speakers up higher and aimed down. Get what acoustical absorption you can into the space but watch that it is appropriately smoke/fire rated and that you don't add so much mainly high frequency absorption that the room is dead at high frequencies but very boomy at low frequencies. Try to minimize stage noise, IEMs may not fit the budget but things like the guitar and bass amps aimed at the players rather than at the audience might help. Think about whether you really need high levels everywhere or only directly in front of the stage. Think about speaker placement and coverage, turning the system up won't really fix it not having appropriate coverage.

Gym mats on the wall probably do more psychologically than acoustically, they may look like acoustical panels but they are made for physical protection and between the finish material, core material and thickness they usually offer limited acoustical benefit.


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## DanAyers (May 10, 2010)

Talented artists?
Sorry couldn't resist.

Take a look at Sound-Seal for fiberglass panels. If you dont mind the colors you might be able to get a few extra panels or cut-offs from a dealer who installed them nearby and had extras.


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## museav (May 12, 2010)

DanAyers said:


> Take a look at Sound-Seal for fiberglass panels. If you dont mind the colors you might be able to get a few extra panels or cut-offs from a dealer who installed them nearby and had extras.


There are many generally similar acoustical panel products available and while in most gyms adding any acoustical absorption can help, the challenge can be using them in an effective manner (and legally as far as flame spread and smoke emitted ratings). There are many factors related to how you locate and mount acoustical treatments that can significantly impact their effectiveness and in many cases there are also options such as implementing diffusion instead of only absorption.

Carpet is acoustically absorptive, but only at higher frequencies. A common problem is using carpeting for acoustical absorption and ending up with a space that is perhaps even overly 'dead' at higher frequencies but very 'live' and 'boomy' at lower frequencies. As an example, put behind a drum kit carpet might significantly reduce the reflections off the wall from the cymbals but have little effect for the kick.

Back to the OP, it would really help if we knew more about the venue, the audio system (especially the speakers) and the event. I have been in many gyms that are an acoustical nightmare but I have also sometimes been there to help change that and there are gyms that have decent acoustics, so knowing more about the situation might help in getting relevant recommendations..


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## MisterTim (May 12, 2010)

museav said:


> Back to the OP, it would really help if we knew more about the venue, the audio system (especially the speakers) and the event. I have been in many gyms that are an acoustical nightmare but I have also sometimes been there to help change that and there are gyms that have decent acoustics, so knowing more about the situation might help in getting relevant recommendations..



Uh...it's a gym. Cinder block walls all around, 40(ish) foot ceiling, full-length basketball court. Divided on one wall by one of those big wooden/metal divider things. 

Last year I had Yamaha S115Vs, but this year I'm using EV SX300s as the mains. S112Vs as monitors.


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## hsaunier (May 12, 2010)

Are there collapsible bleachers in the gym? Consider deploying them as they may trap some low end.


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## BillESC (May 12, 2010)

Can you afford to rent curtains? A couple hundred yards of 26 ounce velour will do wonders in the space.


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## MisterTim (May 12, 2010)

hsaunier said:


> Are there collapsible bleachers in the gym? Consider deploying them as they may trap some low end.


Not in this gym, but in other gyms I've had to run sound in, that's a good idea. 


BillESC said:


> Can you afford to rent curtains? A couple hundred yards of 26 ounce velour will do wonders in the space.


 Could I afford it, probably, but I don't think I would have the time beforehand to hang all that curtain. That would be awesome though and I'll consider it in the future.


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## museav (May 12, 2010)

MisterTim said:


> Uh...it's a gym.


Yes, and I have worked for many schools, churches, school districts, etc. to address acoustics in just such spaces. Acoustical product manufacturer's web sites and brochures are filled with pictures of school gyms with their products in them. And I've seen gyms with 'soft' floors, exposed insulation on the walls and insulation on the ceiling (or 'acoustical' ceilings) that are there to serve other purposes. So one cannot assume that every gym is the same, which is why I asked.

How is the room configured, is the stage on a short end or in the middle of a long side? How are you deploying the Sx300s, is it one per side on sticks? Are they run full range without subs? What do you have for system processing? Can you control the stage monitor and amp levels or is that driving the room levels? Do you have to cover then entire gym or maybe just part of it with lesser coverage in some areas being acceptable?

This general topic has also been discussed before, for example http://www.controlbooth.com/forums/sound/9810-gym-sound-absorbtion-diffusion-panels.html and http://www.controlbooth.com/forums/sound/7521-gym-multi-function-hall-sound-system.html, so you might find something useful by reading those and doing some searching for other similar past discussions.


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## MisterTim (May 12, 2010)

museav said:


> How is the room configured, is the stage on a short end or in the middle of a long side? How are you deploying the Sx300s, is it one per side on sticks? Are they run full range without subs? What do you have for system processing? Can you control the stage monitor and amp levels or is that driving the room levels? Do you have to cover then entire gym or maybe just part of it with lesser coverage in some areas being acceptable?


 Well my main intent was to ask the question in a more general reference to dealing with the usual gymnasium problems, but since we're here anyway:

As far as the gym goes, it's a triple-gym, with the middle gym having bleachers on both sides. The smaller gyms on the outsides are full-sized courts, no bleachers, with one wall being about 75% coverage wooden behind the bleachers of the middle gym. Painted concrete block all the way up to the ceiling (estimate 40', I don't know what a standard height is), which is just metal sheet roofing on truss, or whatever it's called. 

Middle of the long side, against the wall. Assuming the space is a 2:1 rectangle (close enough if it's not exactly) I need to cover a square in the middle. 

Full range, on sticks. I do have subs (400W EVs, unknown model) and more amps, but that's a lot to haul if there's no benefit. Last year I didn't have anything for processing, this year I will have a DBX DriveRack-PA. I have 2 amps, 1 for mains and 1 for monitors, both dual channel, so I can control the monitor levels. 

I just recently heard from the music director that he has a full-enclosure drum enclosure, which, while homemade, will be helpful. 


> This general topic has also been discussed before, for example http://www.controlbooth.com/forums/sound/9810-gym-sound-absorbtion-diffusion-panels.html and http://www.controlbooth.com/forums/sound/7521-gym-multi-function-hall-sound-system.html, so you might find something useful by reading those and doing some searching for other similar past discussions.


For some reason, the search feature often does not work properly for me...I'll assume user error on my part, but thanks for those.


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## AdamC (May 22, 2010)

MisterTim said:


> Full range, on sticks. I do have subs (400W EVs, unknown model) and more amps, but that's a lot to haul if there's no benefit. Last year I didn't have anything for processing, this year I will have a DBX DriveRack-PA. I have 2 amps, 1 for mains and 1 for monitors, both dual channel, so I can control the monitor levels.



I would definitely want subs for a rock show. At least you'd have some low end thump along with the ridiculous gymnasium reverb on everything.

Absorption is the way to deal with the acoustics, obviously. If it has to be temporary, hang lots of curtains, rent pipe and drape, whatever you can manage. Try to make sure your speakers are pointed at the audience not the ceiling, and hope for a large and absorptive audience!


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## WooferHound (May 22, 2010)

My favorite Low Cost sound absorbing material is Carpet Pad. You can find in on the side of the road, at construction sites and in the dumpster at Carpet stores. I glued some up covering the walls in a small room at a church. It worked too good, it sounded like negative sound, or the sound was getting sucked out of my ears.

Another rather Far Out thing to try is to point your speakers directly into the corner that is diagonally opposite from each speaker. Another way to say it is that it is the corner behind the audience that is farthermost from each speaker. I have done this in a huge number of Live rooms, it will make a difference but it will not fix the problem completely. Plus I second the above suggestion to make sure the cabinets are pointed slightly down toward the listeners and away from the Back Walls.

I looked at the speakers that you are using, they are kinda small for the room you are talking about, The band is probably overwhelming your mains system and it will all sound "Distant". I believe that idea suggested above about turning around the bands instrument amplifers and direct them away from the audience. This will make your Sound System more dominant. Also with a system that small I would concentrate on the vocals and bring up the individual instruments as they are doing solos and other things that need to be featured.

Another thing I would do with a smaller system is to limit the amount of Bass you use as this is what will use up most of your power.


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## museav (May 23, 2010)

WooferHound said:


> My favorite Low Cost sound absorbing material is Carpet Pad. You can find in on the side of the road, at construction sites and in the dumpster at Carpet stores. I glued some up covering the walls in a small room at a church. It worked too good, it sounded like negative sound, or the sound was getting sucked out of my ears.


Carpet pad is not only usually a poor choice acoustically, I also believe it is not rated for use on walls in assembly spaces. I can't stress this enough, on a site where we have a thread discussing The Station fire, one of the last things we need is possibly leading people to using 'acoustical' materials that don't do what people think they do acoustically while being potentially dangerous in the application, the very thing that resulted in that tragedy.

Bleachers often act as a Helmholtz slot resonator but that is typically a narrowband absorption and will be at whatever frequency it is. It can often explain why a room seems dead at certain frequencies.

I am a bit concerned about the Sx300 perhaps not being the best choice for the application. Not only may it be pushing them to expect them to fill a gym for a concert, but the nominal 65x65 degree pattern may not be the best choice for the application. Think about where you locate the speakers and how they are aimed so that the pattern can cover all the desired listener area while minimizing the sound aimed at the walls and ceiling rather than the audience. Could be a bit of a challenge with speakers with a nominal 65x65 pattern on sticks. In addition, you have to read the details about the claimed 60-20kHz, +/-3dB response as that is a half space measurement, or with the speaker right against a large reflecting surface. That won't really apply to speakers on a stick, so unless you are indeed using the speakers primarily for vocals and not for kick, bass, etc., then the low frequency response will likely be less than desired and subs probably required to get the desired response and levels.


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## Chris15 (May 23, 2010)

MisterTim said:


> For some reason, the search feature often does not work properly for me...I'll assume user error on my part, but thanks for those.



There's a setting in the user control panel / edit options/ thread display options/ Default age cut off that controls whether threads beyond a certain age show up or not. I suggest you check that setting...


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