I'm working on a rehab project for our school's student center, and we're installing an audio system. The size of the room is 91 feet long, 40 feet wide, with a ceiling height of 12 feet. We have designed the space to have no front, and have arranged 8 speakers to be placed evenly around the long ends of the room. I need help in determining quantity of subwoofers, and locations. The room has been designed to be split in half, and can be controlled independently only using 4 speakers to a half, if desired. With this being said, I would imagine at minimum 2 subs, one for each half. Will one sub suffice for an area of that size? I'm also taking recommendations on speaker/sub brand and sizes. Thanks!
Subwoofer Placement
- Thread starteravaldez
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macsound
Well-Known Member
What is the purpose of the sound system and reason a subwoofer is needed?
I can imagine there being public gatherings held here and usually a single wireless microphone to make announcements or have talks of some sort.
I've worked in a couple corporate spaces that had airwalls and no definite front with processing anticipating a subwoofer, permanently mounted amp wired to 2 locations in each room and if an event warranted using the sub, it was rolled out and plugged in with a nice 5' speakon cable.
I can imagine there being public gatherings held here and usually a single wireless microphone to make announcements or have talks of some sort.
I've worked in a couple corporate spaces that had airwalls and no definite front with processing anticipating a subwoofer, permanently mounted amp wired to 2 locations in each room and if an event warranted using the sub, it was rolled out and plugged in with a nice 5' speakon cable.
The student center will also be used for major school events, so audio reinforcement will consist of guest speaker presentations, and video. With it being primarily a student center, administration anticipates the space being used for school dances as well, so the system would be used to play music.
jkowtko
Well-Known Member
That's not a huge room ... can you provide a diagram of your planned speaker placement, a few photos of the space, make/model of the currently planned speakers, describe the wall surface, and type of audio programming you are planning on?
If you plan to run audio for dances, then you probably want good bottom end and the choice of subs will likely depend on your full range speakers. If you are only planning for ambient music then subs may not be needed.
If you plan to run audio for dances, then you probably want good bottom end and the choice of subs will likely depend on your full range speakers. If you are only planning for ambient music then subs may not be needed.
macsound
Well-Known Member
From my experience with rooms with no defined "front" is dealing with the simple issue - speakers should always be in front of the microphone.
And even though not a "huge" room, I can imagine with kids standing and no chairs, getting a PA to overcome 1000 rowdy kids isn't as easy as it sounds.
And even though not a "huge" room, I can imagine with kids standing and no chairs, getting a PA to overcome 1000 rowdy kids isn't as easy as it sounds.
The presenters would be placed in front of the speakers either way. We're also a small school of only 400 students, if that makes a difference.
Attached is a drawing with speaker placement identifed as an S in a small circle inside the great room, there are currently 8 listed. We are in the early stages of the project so no speakers have spec'd out yet.
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macsound
Well-Known Member
I'm assuming based on the location of the speakers in the drawing that the architect (or whoever) was planning on speakers being flown facing toward the center, vs pendants.
Had great experience with the JBL CBT 50-LA, and their slim profile and availability in 2 colors makes them great for this hanging orientation.
Had great experience with the JBL CBT 50-LA, and their slim profile and availability in 2 colors makes them great for this hanging orientation.
@avaldez If I'm understanding correctly, each half of your space will measure 91' long by 20' wide. Three thoughts:
a; Each half may not be considered large but the width will be appreciably less than the length which is less than ideal for many / most uses.
b; When you divide your room with any manner of temporary / conveniently movable wall (commonly referred to as an air wall) any sub woofer worthy of the term on either side will result in 'thumps' being heard (desired or not) in the other half of your space. A choir rehearsing on one side likely won't appreciate the calisthenics / fitness warm-ups to accompanying rock music on the other side nor will a teacher monitoring an algebra exam while the cheerleaders are rehearsing on the other side.
c; I guess my point is: You'll have less then desirable acoustic separation between the two halves of your space, and that's before you've provided any manner of sub woofer.
@MNicolai @TimMc @Anybody: Care to comment?
Toodleoo!
Ron Hebbard
Have you talked to any acoustic/sound consultant? I should hasten to add that I'm not one by a long stretch.
Have you given any thought to having an array of in-ceiling speakers (or perhaps the ceiling construction makes that impossible)? Having them on about 10' centers would mean 36 speakers, and I suspect would give more even coverage over the area. One or more subwoofers could of course also be incorporated (as could some non-installed PA system if deemed necessary). Overall sound fidelity might suffer a little, depending on one's budget for speakers, but still could be quite decent. Low bass (as in dance music) would undoubtedly require the addition of one or more subwoofers.
Have you given any thought to having an array of in-ceiling speakers (or perhaps the ceiling construction makes that impossible)? Having them on about 10' centers would mean 36 speakers, and I suspect would give more even coverage over the area. One or more subwoofers could of course also be incorporated (as could some non-installed PA system if deemed necessary). Overall sound fidelity might suffer a little, depending on one's budget for speakers, but still could be quite decent. Low bass (as in dance music) would undoubtedly require the addition of one or more subwoofers.
Never have speakers pointed toward each other. Deigned for it, or not, there needs to be a specified front in each half of the room, on the same sides. That way, you'll only need two speakers per half, and they can be operated as pairs or together as mains and delays. Doing it any other way just wastes money and makes for an acoustic mess.
More subs are not better in terms of coverage because they cancel with each other. The subs are only needed for dances, rallys, and such, where music is the key element. Use a single, cardioid subs on wheels placed at the "main" end of the room. Roll it away when it isn't needed.
More subs are not better in terms of coverage because they cancel with each other. The subs are only needed for dances, rallys, and such, where music is the key element. Use a single, cardioid subs on wheels placed at the "main" end of the room. Roll it away when it isn't needed.
Jay Ashworth
Well-Known Member
The subs must be inside the room.
As long as you have them crossed over low enough (40-60Hz, I think), it doesn't matter where you put or aim them, as long as they're not face-to-wall-touching. LF audio is amazingly non-directional.
But indeed, you probably don't need "real" subs, with 18" cones, heavy duty coils, separate amps, short cables, and an active crossover...
As long as you have them crossed over low enough (40-60Hz, I think), it doesn't matter where you put or aim them, as long as they're not face-to-wall-touching. LF audio is amazingly non-directional.
But indeed, you probably don't need "real" subs, with 18" cones, heavy duty coils, separate amps, short cables, and an active crossover...
Sigh.
The last thing I'd want to see is subwoofers in a multi purpose environment where the students (and some teachers) have access to controls. The money spent to make it idiot-resistant will result in disappointing performance, and once the kids figure out how to bypass the protective constraints on the system, the subs will be confetti.
It's the nature of the youthy beast to turn up everything as far as it will go. Only the most clever and secure designs will win, and like on GoT, if you don't win, you die.
The last thing I'd want to see is subwoofers in a multi purpose environment where the students (and some teachers) have access to controls. The money spent to make it idiot-resistant will result in disappointing performance, and once the kids figure out how to bypass the protective constraints on the system, the subs will be confetti.
It's the nature of the youthy beast to turn up everything as far as it will go. Only the most clever and secure designs will win, and like on GoT, if you don't win, you die.
Ben Stiegler
Well-Known Member
Ceiling grid music quality speakers have many advantages here, including even sound levels thru the space. Take it a step farther and use POE speakers, add a proper DSP and touch screen control, and u will hugely improve the acoustics and speech intelligibility by being able to time align signals from speakers based on where today’s “front” is located. JBL and others make a ceiling grid sub which will never get damaged by spilled coke, etc. I can help you design and budget (in July, tho).
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