# Church Auditorium Speaker Placement



## niccosuave (Jul 15, 2013)

Hello All,

I currently work for my church and we've been in our building for about a year and a half. We have the same PA system that we had when we were mobile and haven't upgraded anything since. Where everything is placed right now there is not an even spread of an overall consistent sound, mainly during worship. 

We're trying to re-position our speakers so that we have an even coverage throughout the auditorium, as well as figure out the best way to mix for the different sections. Here is our system:

Yamaha LS9-32: 
| Omni 1/2 --> Drive rack --> Highs --> (2) Mackie SR-1530 [Mains] 
Lows --> (2) EV TX-2181 [Subs]
| Omni 3 --> (2) Mackie 450 [In-fills]
| Omni 4 --> (2) Mackie 450 [Out-fills]

Right now the fills are set to post fader, and have there own levels on 2 different mix groups, making the sound engineer (volunteer for the weekend) mix 3 different layers!

We'd like to have the fills set to pre, and everything set to nominal. Also re-positioning the fills. 

This is an overhead of our our auditorium is set up currently with seats:
http://imageshack.us/a/img713/7589/6co.png

Here is a close up of the direction the speakers are facing:
ImageShack® - Online Photo and Video Hosting

The height of the room is 18' 3" from floor to beams. Our fills are aimed like so:
http://imageshack.us/a/img854/7401/d0te.jpg
http://imageshack.us/a/img856/5716/0o0t.jpg

We're stuck as to how to better the equipment we have. How to aim, where to aim. How to patch out of our LS9.

Any help will be very much appreciated!

-Nicolas Hirajeta


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## DaveySimps (Jul 15, 2013)

Welcome Nicolas. I have relocated your thread to the Sound Forum so it is in the proper place. When you get the opportunity, stop back by the New Member Board and introduce yourself to the rest of the group.


~Dave


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## museav (Jul 16, 2013)

Am I viewing those images right that the front fills are flown while the mains are ground stacked on the subs? Are your 'in fills' aimed to both cover the same seating area as they appear in the pictures or is each covering one half of the that seating? You mention two mixer outputs to the mains and subs but are they run as stereo or dual mono? And as they are front fills for the audience, why do you want the front fill signals to be pre-fader?

Are you having to work with just what you have or is there any opportunity for changes or additions? The results might be a lot better and it might make it easier to achieve your goal if you had a larger system processor that could handle all of the outputs and provide EQ, delay, filtering, etc. for the mains, subs and fills.


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## niccosuave (Jul 16, 2013)

Yes you are viewing them correctly. Currently the 'in fills' are aimed to 'cross-cover' the center section. Which are two, 8 seat by 7 seat, sections.

shows the current speaker placement and angle coverage. Red shows the mains and subs, blue shows the fills.

The mixer outputs are stereo, LR, that go to a drive-rack, DBX
, the subs get the low output and the mains get the high's. The fills currently come straight from the LS9 mixer. 

The fills are receiving a mix group, in for ins and out for outs. They are post-fader and have their own mix also. What I meant to say was we want them POST-fader with their channels set to nominal.

We currently have to work with what we got and are trying to make the best possible use from it. Our most difficult issue is the width of the room, and having the sound evenly throughout. We currently can use a (2) 32-band EQ on the mains and fills.

Thanks for the reply!


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## WooferHound (Jul 16, 2013)

If it was me . . . I would hang all the speakers except the subs over the front of the stage in a single cluster and aim the 4 speakers at the 4 seating areas. If you run something PRE fader then you will not be able to turn it off with the fader. Use the LEFT Main to feed your Mains speakers and the RIGHT Main to feed your Fill speakers.


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## niccosuave (Jul 16, 2013)

How would you hang the 1530's? I see no rigging points.


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## museav (Jul 17, 2013)

Several simple points to consider:

1. There is no way two nominal 90x40 SR1530 speakers can provide 'stereo' coverage of your seating, you'll be lucky if each can cover half of it. With your seating arrangement and some of it wrapping around part of the stage anything other than mono will likely require a more complex system and more equipment.

2. Since the fills are mono you probably do not want two covering the same seating area.

3. You often want to get the mains up higher if possible as that typically allows for more even coverage, but in this case the SR1530s cannot be flown or even pole mounted. Conversely, front fills are usually located lower since they are typically used to cover only the first few rows and having them physically lower can help with the related aural image being down at the stage rather than a 'voice from above'.

4. A system processor that can take a single room audio mix, whether mono or stereo, and internally handle all the related mixing, routing and processing for the speaker system may make the system operation simpler. That may mean a more fully featured processor to support the system as you use it or the existing DRPA used with a simplified speaker system.

The challenge is that what you have was selected for what is essentially a different application so it may not translate that well to your current situation. You could try doing things like turning the subs on their sides so the SR1530s are lower and maybe moving them more toward the center and aimed further out, that might eliminate some of the need for front fills. You could also try one 450 covering each seating section and see if that works without using the SR1530s at all.


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## niccosuave (Jul 17, 2013)

1. The set up we currently have was designed by our old sound guy. We're not trying to only use the 1530s, we're trying to figure out the best method to use what we have working together. I am not sure as to why we do run a stereo signal because nothing is panned nor are we receiving a stereo signal. This is just how the old sound guy set it up.

2. The fills weren't filling like they were supposed to. There were hot spots, as well as cold ones and that is what we're trying to eliminate. The center section that needs coverage is 35' wide x 22' deep. With how shallow our auditorium is, the front row is less than 4' from the stage.

3. The only place for the front fills to be close to the ground would be next to the main and then cross aiming them again, which doesn't sound like a good idea to me.

4. I don't know too much about the DBX PA drive rack, but I am reading the manual on it now. I know it has a stereo in, and 3 stereo outs: low, mid, high. We're currently only sending the lows and highs and not using the mids. Is that a problem?

I know what we have was intended for a different application but we're trying to figure out the best method to use it where we are now. I would love to have the subs on the sides, that's how they were when we were mobile. If they were, the 1530s horn would no longer be at its proper height. We have been testing around, turning off certain speakers and using different combinations to hear where they reach. 

Thanks for the reply


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## TimmyP1955 (Jul 20, 2013)

Part of the problem is that you have too many arrival times owing to the mains and fills being so far apart. I expect you can use delay to make it better in some places, and worse in others.

Part of the problem is that the dispersion of your loudspeakers varies greatly across the frequency spectrum. As such, you have very inconsistent acoustical combining and cancellation.

IME the only affordable loudspeaker that arrays reasonably well is the Yorkville U15. A center cluster would need over 180 degrees of coverage and would likely be a feedback nightmare. So two clusters of two hung on the posts might be about right.

Or you could shoot things the long way as any architect with a clue about sound would have done.


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