High School Gym Sound Setup

[martydale14]

I get to do something fun this Sunday at the high school in town. The dance team is hosting an event where there will be dance teams from other schools participating in showing their routine, and they asked me to run the sound for the event. In the attached picture, the main floor is where they will be dancing. They will be walking down onto the floor from the middle of the stage (there will be stairs in place). The bleachers for the seating area are on the right side of the picture, which you can't see. My question is, where would be the best place to position my speakers? I have 4 tops and 2 subs, which is enough sound because this is a fairly small gym, and I've done school dances in this gym before.

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[jayhwk]

Will you be doing live sound as well as music playback? What kind of speakers do you have? Can you draw a floor plan for us?

I see an installed house system that's flown. If you can use that for speech and your system for music, you will probably have better results. The house system looks properly designed for speech, but you will have to verify it covers the audience on site. I see a some acoustic panels in the ceiling which is a good sign. Leave as much of the curtain exposed as you can to keep the reverberation time as low as possible.

[martydale14]

Will you be doing live sound as well as music playback? What kind of speakers do you have? Can you draw a floor plan for us?

I see an installed house system that's flown. If you can use that for speech and your system for music, you will probably have better results. The house system looks properly designed for speech, but you will have to verify it covers the audience on site. I see a some acoustic panels in the ceiling which is a good sign. Leave as much of the curtain exposed as you can to keep the reverberation time as low as possible.

Thanks for the reply. There will be an announcer at the event, so I will provide a microphone for her, as well as the music playback. The speakers I have are two Peavey PR15, two Alto TS112, and two Peavey PV118. The house system is good for speech, but I plan on using my system since it will already be up and running. I will work on drawing out a floor plan.

[DJzrule]

I would do 2 tops per side, facing the bleaches, that way you don't have to crank it and can try to avoid nasty echoing because of blasting sound from across the room. 1 sub per side if possible, or clustered in the middle by the stage.

[jayhwk]

Thanks for the reply. There will be an announcer at the event, so I will provide a microphone for her, as well as the music playback. The speakers I have are two Peavey PR15, two Alto TS112, and two Peavey PV118. The house system is good for speech, but I plan on using my system since it will already be up and running. I will work on drawing out a floor plan.

You could probably throw up the Peaveys on sticks on either side of the stage with subs clustered in the middle and have an acceptably good sounding result for the music.

If you're dead set against using the house system for the speech, you will have to take some extra steps beyond the responsibilities of a normal mobile DJ. You will probably need a mixer (even a Mackie 1202 will do), a parametric equalizer, and a digital delay in order to properly design and tune the system. The name of the game will be intelligibility and directional realism. You will need to get the speakers high up and close to the audience because the gym is probably pretty reverberant even with the acoustic treatment. You will also need to pick your "source" location and delay the loudspeakers so that the sound arrives from all the speakers in the proper order. I would think about making the stage your "source" with the PR15s (at a low level so they don't energize the whole room) and use the TS112s on delay lines much closer to the audience doing the main reinforcement.

Once you have the system set up, tune it by having an assistant "talk" the microphone - read a book, etc... while you sit in the audience with the parametric EQ (inserted on the microphone channel in question) and make adjustments. A DSP with remote control is really useful here, or you can pull the EQ out of the rack and use long microphone cables. Measurement equipment like a SMAART rig can make this process easier but it is also quite possible to do it by ear.

[DJzrule]

You could probably throw up the Peaveys on sticks on either side of the stage with subs clustered in the middle and have an acceptably good sounding result for the music.

If you're dead set against using the house system for the speech, you will have to take some extra steps beyond the responsibilities of a normal mobile DJ. You will probably need a mixer (even a Mackie 1202 will do), a parametric equalizer, and a digital delay in order to properly design and tune the system. The name of the game will be intelligibility and directional realism. You will need to get the speakers high up and close to the audience because the gym is probably pretty reverberant even with the acoustic treatment. You will also need to pick your "source" location and delay the loudspeakers so that the sound arrives from all the speakers in the proper order. I would think about making the stage your "source" with the PR15s (at a low level so they don't energize the whole room) and use the TS112s on delay lines much closer to the audience doing the main reinforcement.

Once you have the system set up, tune it by having an assistant "talk" the microphone - read a book, etc... while you sit in the audience with the parametric EQ (inserted on the microphone channel in question) and make adjustments. A DSP with remote control is really useful here, or you can pull the EQ out of the rack and use long microphone cables. Measurement equipment like a SMAART rig can make this process easier but it is also quite possible to do it by ear.

While this is the proper way to tune the room, its overkill for his situation. Sounds like basic PA and DJ services to people in bleachers. If his tops are near the bleachers facing directly at the people, high up enough on stands, then he'll be fine. In an more ideal situation, he could put the subs at the stage like I mentioned earlier and delay them to match the tops, but that seems a bit advanced for him since he didn't mention having a DSP.

[martydale14]

DJzrule, you are correct. I do not have a DSP. The mixer I have is the Behringer XENYX 1002B and the amplifiers I have are QSC GX5s.

[jayhwk]

While this is the proper way to tune the room, its overkill for his situation. Sounds like basic PA and DJ services to people in bleachers. If his tops are near the bleachers facing directly at the people, high up enough on stands, then he'll be fine. In an more ideal situation, he could put the subs at the stage like I mentioned earlier and delay them to match the tops, but that seems a bit advanced for him since he didn't mention having a DSP.

I'm just sick of hearing muck in high school gyms. Back when I was in high school out of all the dances/DJ-type events in the gymnasium I attended - maybe 12 or so - I couldn't understand a single word out of the mic the whole night, even when the music sounded decent. The "awards" show in the middle was always particularly painful. They would get all the kids out up on the bleachers while the prom court walked out, and it would be embarrassing that no one could hear their names. Eventually (at my suggestion, even as a student), the school stopped allowing the DJs to use their sound systems for speech, period. The house system wasn't great, but it had a proper high pass filter, something resembling a house EQ curve, and a decent microphone which finally made things bearable.

Depending on the reverberation time of this gym, the OP may be able to get away without a DSP. I seriously doubt he can go without an EQ or a mixer. You can do it without the delay, but you will sacrifice the directional realism, which I consider to be the second most important aspect of running sound. There's nothing worse than having someone talking to your right and hearing it from a loudspeaker that hasn't been properly delayed pointed at your left ear. Un-naturalness like that ruins otherwise good sound systems.

The people paying a sound system provider for an event like this are hiring with the expectation that every seat in the audience will be able to understand every word. That's the most basic rule of providing sound systems for speech. If the sound system provider can't do that, he shouldn't have signed a contract saying he could.

[DjNeedleSharp]

Not trying to be rude but myself as well as many people on this board would agree that the speakers you listed are not "enough" for any larger gig so any configuration you go with will only be the "least shitty way." Since I'm pretty sure both those cabs are 70-90 degree dispersion angle cabs, you will have massive cancelation and comb filtering regardless of whatever practical way you set this up. Only way around it is if you have some kind of sound management processor like a DBX driverack or any other way to delay the second set of tops... Since that probably isn't the case, I'll go ahead and make a suggestion that I will probably get shit for... but whatever.
http://i75.photobucket.com/albums/i299/needlesharp/f897868a-c380-443f-aeb8-68bf2a580415_zps5ecde6bb.jpg
Notes about the setup:

the subs need to be next to each other, facing into the corner of the room with the cones about 12 inches from the wall. Without getting all technical, this is your best chance at getting good bass in that room.
If this sounds bad (maybe 10% chance?) the subs need to be NEXT TO EACH OTHER against a wall facing out towards the bleachers.
plug into the house PA. Have someone play a song and turn the volume up and down and see if it sounds better or worse in the bleachers... You will have more comb filtering but you may get better coverage
The PR15s need to be on stands as high as they will go and facing STRAIGHT out (not angled inwards)
The Alto's need to be closest to the crowd facing in. If you have cables that are long enough to have the PR15s closest to the crowd, you can swap the them but I figured you would have some super long hot cables and them you would run into power loss and other crap.
when you test to see how the speaker configuration sounds, to start with, do so one at a time. The process would go as follows: 1. setup and plug in all the speakers as you intend, 2. unplug everything, 3. Plug ONE sub in and play a song. 4. Plug both subs in and make sure it sounds louder, 5. unplug subs and plug in both PR15s and check, 6. unplug all, plug in Altos and check. 7. plug in altos + PR15s and check, 8. turn up house PA with all tops and check, 9. add subs and check all together. 10. Reposition PR15s as needed to decrease echo.


I know the subs in the corner thing sounds crazy but long story short, it should sound at least twice as loud as splitting up the subs like most people do. Sometimes (rarely) things happen and it sounds better if you just put the subs against a wall. But: the subs should ALWAYS be: 1. next to each other, 2. on the ground, 3. either against or facing a wall OR corner. These (for simplicity) are not negotiable.

Splitting up your tops will give you the best coverage. If you DO have a speaker management system, state so and that changes the game a bit. If not, you'll survive.

[DjNeedleSharp]

I'm just sick of hearing muck in high school gyms....If the sound system provider can't do that, he shouldn't have signed a contract saying he could.
Lol dude come on... This is somebody who is looking for the best way to set up his pair of $200 active tops and $200 passive tops with some entry level passive subs. Nobody at that event will even knows what DSP or high pass filter means let alone directional realism.

Yes I completely agree with the statements you are making and personally don't think he has adequate gear but you are talking out of the scope of the problem. He is probably getting paid little to nothing to do a fun side gig and supply some sound for a school function. Nothing crazy... Let's take this as a challenge and see what we can come up with without saying "go buy this and this."

[Brandt Slater]

Why are you putting the subs in the corner? You're anchoring the low end to one side of the spectrum which isn't natural to the ear. Putting the subs in center is the most natural sounding as it will cover your audience.

Oh and since when do you need subs only on the ground? Don't get out much do you?

[DjNeedleSharp]

It's called boundary loading, may you don't get out much. Since his low end is very lacking he could benefit from the extra boundary since we don't even know if that stage is hallow or filled. If you read my two posts you would see that since I considered his lack of adequate gear in my layout, I tried to put together the best SPL for the low-end and least comb filtering for the tops. Is comb filtering natural to the ear? No but unless you wanna tell him to ditch his entry live wide angle tops then it's gonna happen. I'm guessing your answer to that is for him to spend $500 on a DSP? Lol...

Instead of being an arrogant prick you're more than welcome to draw your own layout and writeup yourself. I already said that not everyone would agree with it and for him to test both the corner loaded subs and wall loaded.

Good people person I can tell.

[Brandt Slater]

I am a good people person. Thank you for noticing. However I'm pointing out you flawed drawing. The op was already given the answer a few posts ago. Placing the subs in the center. Do you go to the movies? Concerts? Where's your low end coming from? Not the side. Correct? So why are you telling the op to put them in a corner which is gonna produce far more energy isolated in one corner.

[DJzrule]

Corner loaded would be fine if the speakers were directed onto the dancefloor. However since I advised putting the speakers toward the bleachers a few feet from the front, then the subs wouldn't benefit the crowd at all corner loaded.

[jayhwk]

It's called boundary loading, may you don't get out much. Since his low end is very lacking he could benefit from the extra boundary since we don't even know if that stage is hallow or filled. If you read my two posts you would see that since I considered his lack of adequate gear in my layout, I tried to put together the best SPL for the low-end and least comb filtering for the tops. Is comb filtering natural to the ear? No but unless you wanna tell him to ditch his entry live wide angle tops then it's gonna happen. I'm guessing your answer to that is for him to spend $500 on a DSP? Lol...

Instead of being an arrogant prick you're more than welcome to draw your own layout and writeup yourself. I already said that not everyone would agree with it and for him to test both the corner loaded subs and wall loaded.

Good people person I can tell.

Brandt works for Clair, the largest production company in the United States. He knows what boundary loading is.

To put it bluntly, your proposed set-up will not work. Since sound travels much slower than light, the speakers closer to the audience must be delayed so that the sound arrives from the PR15s by the stage first. Sound travels about 1ft/ms, so if the stands are 50 feet away from the stage the Alto speakers need to be delayed by 50ms. This is a totally different phenomenon than comb filtering - it is called the Haas effect. Humans can hear two distinct arrivals between 8 and 30ms and still make sense of the program material, but any delay between the two arrival times longer than 30ms and the program will be completely unintelligible. You can try this yourself with a recording software like Audacity. Import the same speech track twice and play it back. Them bump the second track back in time in 5ms increments. About the sixth try, you won't be able to understand the speech any more.

As far as "corner loading" - I have done it before to make things work, but if the sound source is not in the corner, then it can often sound "heavy" on one side. I much prefer center or slightly off center clustering - if you need more output by another sub.

The benefits of boundary loading are also sometime overstated: http://www.synaudcon.com/site/author/pat-brown/how-boundaries-affect-loudspeakers/

[sss18734]

It's called boundary loading, may you don't get out much.


Brandt works for Clair, the largest production company in the United States. He knows what boundary loading is.

I definitely lol'ed at this interaction

[Brandt Slater]

Dj Sharp. Firstly let me apologize if I sounded arrogant to you. It's been a long three weeks of moving gear around and training a few new hires and last night I was just done. My apologies for that.

The drawing you provided, the placement of the full range boxes would be the correct positioning and its what I would do if I only had four to work with. In this case it's zone distribution. However a boundary loaded sub in this scenario would actually hurt the response. Subs are slow responders and in this wide room they could produce weird reflections and funky time corrections in conjunction with full range boxes. Which is why placing the subs in the center together is the best option as it will stay correct within the mains and more directional to the ear. But as Jay pointed out, your bleacher speakers would need to be delayed to the mains. Subs won't need it as they're already within the lines of the mains. IMO, if I were the op, I would tap into the house pa to get more coverage with my pa since you'll be lacking center coverage. But only put vocals in the house system and let the other stuff carry the music.

[DjNeedleSharp]

Brandt, thanks for pointing out specifically what the two issues were with that setup. I corner load about half the time in larger venues such as gyms and don't have any issues but this is mostly just recorded music playback and the audience is in the center of the floor so it works fine for me.

jayhwk, lots of us stupid mobile guys corner load all the time. Sorry we can't just go out and buy a bunch more cabs whenever we need to. I've never had a complaint about my sound at a gig and get nothing but compliments. I am familiar with the haas effect however there are other variables such as echoes that create natural delays that can wash out a small difference in cabs. I've been forced to do 40-50 ft back from FOH for side fills (w/o delays... long story) without any huge problems. It's not ideal but it's a lot better than the house PA.

I didn't think about putting the subs in front of the bleachers and didn't see it since the post was before mine (posted while I was writing my first post). The problem here is that you still need some kind of fill for the middle so the dancers can hear the music to dance to. Would probably be best to run the altos facing towards them for center fill towards the stage and the PR15s towards the bleachers since the PRs should be a good bit louder.

[martydale14]

Here is what I ended up doing at the event today...

http://www.facebook.com/photo.php?fbid=579479885398024&set=pb.182767538402596.-2207520000.1362961887&type=3&theater

http://www.facebook.com/photo.php?fbid=579479848731361&set=pb.182767538402596.-2207520000.1362961887&type=3&theater

[Brandt Slater]

Here is what I ended up doing at the event today...

http://www.facebook.com/photo.php?fbid=579479885398024&set=pb.182767538402596.-2207520000.1362961887&type=3&theater

http://www.facebook.com/photo.php?fbid=579479848731361&set=pb.182767538402596.-2207520000.1362961887&type=3&theater

Looks good. Did you use the house system or were you able to cover the center with the PR's. Altos for bleachers.

[DJzrule]

Here is what I ended up doing at the event today...

http://www.facebook.com/photo.php?fbid=579479885398024&set=pb.182767538402596.-2207520000.1362961887&type=3&theater

http://www.facebook.com/photo.php?fbid=579479848731361&set=pb.182767538402596.-2207520000.1362961887&type=3&theater

Looked good for that situation. However looking at your other pics.....cmon man, lose the police rack lights. They literally belong on top of a police interceptor.

[martydale14]

Looks good. Did you use the house system or were you able to cover the center with the PR's. Altos for bleachers.

I ended up using just the Altos on the stage with the subs on the floor. Didn't use the house system at all. It actually sounded really good, surprisingly.

[martydale14]

Looked good for that situation. However looking at your other pics.....cmon man, lose the police rack lights. They literally belong on top of a police interceptor.

Thank you. I got those lights for free, so I figured I would use them. Drunk people get a kick out of it, especially at the bars. Haha