General PA Setup - not BFM (yet) Looking for thoughts

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Vinnyw
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Location: Charlotte, NC

General PA Setup - not BFM (yet) Looking for thoughts

#1 Post by Vinnyw » Sun Sep 18, 2016 1:55 pm

All,

I thought I'd ask here because of the wealth of knowledge and experience that Y'all have.

I go to a church with a conventional direct-radiating setup. FOH mains are 4 JBL SP-215-9 (or look like them; I used to own a pair myself - sold them to build BFM) and 4 QSC KW181 that are located under the tall platform which puts the subs behind a lower 8' radius platform. The FOH mains are combined in pairs side by side - like everyone configures them - and are about 2' in front of the tall part of the platform on either side. The room is a typical pole building which is about 75' X 120' with a full basketball court with 20' walls; the stage and everything is at one end. The console is a Behringer X32; all speaker processing is done in the console.

They would like to do a PA reset in a few weeks to correct a few issues and to clean up several of the permanently-temporary modifications made to the interconnects over the past 3 years.

Some of the folks involved are "professionals" - which tends to mean to me that they partly hear with their eyes. In order to obtain the latitude to improve the system by introducing better solutions later, I have to prove myself by improving what is there already.

In considering the subwoofer placement sticky, I'm thinking that we might be better off moving the subs to the one available corner in order to corner load them. The sticky (rightfully so) doesn't discuss doing this with "conventional" subs, does the same set of guidelines apply? Should I stack them in a 2 X 2 and corner fire them, or do I need to do something else, or are they better off being left where they are now? It feels to me that the lower platform in front of this horizontal array of subs is providing some form of loading that may or may not be helpful. A concern with moving them to the corner is the delay due to the subs being 16 to 18' behind the mains; are there other things that I should be thinking of as well?

The FOH in this space - as you can imagine - is not set up correctly; the direct field ends after the first 5 or 6 rows of seats; the console is entirely in the reverberant field. I'm not in a position to address that now; I'm thinking that OT12J would be a good choice - eventually. The first thing I'd likely address gear-wise is to get them to put WH8's in place instead of the Yammy powered speakers that they are using now. One step at a time, I guess. I'll start to work on cost-effective room treatments next (nasty 250 to 300 hz resonance).

All this makes me wish that I'd completed my DR200 build along with 4 T39s so that I could temporarily (yes, I know) audition them to demonstrate how it could sound without moving any of the existing gear.

I appreciate any thoughts that y'all might have.
Vinny

DR200 Build X 4
Planning WH8 build
Contemplating a sub build...

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Tom Smit
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Re: General PA Setup - not BFM (yet) Looking for thoughts

#2 Post by Tom Smit » Sun Sep 18, 2016 10:39 pm

The subwoofer sticky applies to direct radiator subs as well.

In regards to room treatment, I advice caution. The room/sanctuary is used for more than one circumstance (preaching, live music, drama, congregational singing), therefore study this area well and it could pay dividends.

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TomS

CoronaOperator
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Re: General PA Setup - not BFM (yet) Looking for thoughts

#3 Post by CoronaOperator » Sun Sep 18, 2016 10:52 pm

Being in a permanent install gives you a luxury that most don't have in that you have time to try out every possible location for the subwoofers. The sticky helps people get a workable solution quickly but inside sometimes other variables are at play. Things like building resonances and room modes indoors are impossible to predict even with software. The good thing is that an afternoon, some volunteers, and a dolly and you can pretty much try the subs in every feasible location and using your ears you can best determine where they work the best.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

Vinnyw
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Joined: Sat Sep 26, 2015 10:04 pm
Location: Charlotte, NC

Re: General PA Setup - not BFM (yet) Looking for thoughts

#4 Post by Vinnyw » Mon Sep 19, 2016 12:19 am

Thanks. I thought that the basic concept was the same. I searched for additional information, but every search term I thought to use was thrown away because it was too "common"... Does it matter with Direct Radiating subs if the cones are directed toward or away from the corner?

Most of the other applications for the room will also benefit from some treatment. Anything utilizing live or recorded music would be using the PA, so deadening the space won't cause any forseeable problems.

I haven't had time to go through and run waterfall plots to quantify the primary culprits. The room gets out of control when pushed much above 100dB in the reverberant field.
Vinny

DR200 Build X 4
Planning WH8 build
Contemplating a sub build...

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Chris_Allen
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Re: General PA Setup - not BFM (yet) Looking for thoughts

#5 Post by Chris_Allen » Tue Sep 20, 2016 2:42 am

Vinnyw wrote: but every search term I thought to use was thrown away because it was too "common"...
Avoid two/three letter words and you might get some better results - the search tool is rubbish!
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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Svartrose
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Re: General PA Setup - not BFM (yet) Looking for thoughts

#6 Post by Svartrose » Sun Mar 12, 2017 7:26 am

Corners are often behind a band or DJ. Is it a good idea to place subs there?

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DJPhatman
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Re: General PA Setup - not BFM (yet) Looking for thoughts

#7 Post by DJPhatman » Sun Mar 12, 2017 1:39 pm

Vinnyw wrote:Does it matter with Direct Radiating subs if the cones are directed toward or away from the corner
Face the drivers into the corner or wall. I think, in a room that huge, placing 1 sub on each wall of the room to help even out the sound would be a better approach. Are you trying for concert level sound? I know of christian rock sanctuaries that rock out 120dB+.
Large room.jpg
Thoughts, Brent?
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Svartrose
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Re: General PA Setup - not BFM (yet) Looking for thoughts

#8 Post by Svartrose » Sun Mar 12, 2017 2:21 pm

Svartrose wrote:Corners are often behind a band or DJ. Is it a good idea to place subs there?
Already found the answer: it is a bad idea.

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