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Title: Midsized festival -> Line Array
Post by: Tijs Proost on December 27, 2013, 07:24:06 AM
Hi all,

I'm in the organising team of a midsized festival (1500pl) in Belgium, recently whe received new regulations that require us to redesign our audio setup. LAeq,60min ≤ 100 dB(A) is the new benchmark, currently our setup is very basic, woofers and speakers blasting the sound in the crowd.

We want to keep our sound level in front of the stage @  LAeq,60min ≤ 100 dB(A) and keep the rest of the area more quiet to give the crowd the chance to rest and have a drink.

We have had numoures offers al presenting us a Line-array system. It is quite an investment but is it worth the money? What is your opinion? is it enough to just keep the current speakers and raise them of the floor or do we realy need the line array to give the crowd a desent sound quality?
Title: Re: Midsized festival -> Line Array
Post by: TJ (Tom) Cornish on December 27, 2013, 07:43:22 AM
Hi all,

I'm in the organising team of a midsized festival (1500pl) in Belgium, recently whe received new regulations that require us to redesign our audio setup. LAeq,60min ≤ 100 dB(A) is the new benchmark, currently our setup is very basic, woofers and speakers blasting the sound in the crowd.

We want to keep our sound level in front of the stage @  LAeq,60min ≤ 100 dB(A) and keep the rest of the area more quiet to give the crowd the chance to rest and have a drink.

We have had numoures offers al presenting us a Line-array system. It is quite an investment but is it worth the money? What is your opinion? is it enough to just keep the current speakers and raise them of the floor or do we realy need the line array to give the crowd a desent sound quality?
Per forum rules, you need to change your forum username to be your full real name.
Title: Re: Midsized festival -> Line Array
Post by: Tijs Proost on December 27, 2013, 08:20:44 AM
Per forum rules, you need to change your forum username to be your full real name.

Done!
Title: Re: Midsized festival -> Line Array
Post by: g'bye, Dick Rees on December 27, 2013, 08:28:08 AM
Done!

What equipment are you using now (brand/model)?

How is it deployed?  It would seem you are ground stacking, but how high do the stacks reach?

What are the dimensions of the listening area?  How deep, how wide?

What other buildings, activities, etc surround the area where you operate?  Who are the neighbors?
Title: Re: Midsized festival -> Line Array
Post by: Tijs Proost on December 27, 2013, 12:27:56 PM
I added a picture of the current stack (JBL . Back then we had a crowd of around 1000pl.
This year we are expecting to have 1500pl, we are creating a larger area for the crowd to listen to the bands.

The second picture shows the area we used this year, the crowd will be standing around 40-45m away from the stage over an area 30-35m wide.

The surrounding area is plain field.

Should we ether go larger with the current stack or will the investment of hiring line-arrays make the difference? (it will cost arround €1500 plus for the line array and €1000 for 2 pa towers and rigging)

Title: Re: Midsized festival -> Line Array
Post by: Mark McFarlane on December 27, 2013, 01:48:19 PM
...
We want to keep our sound level in front of the stage @  LAeq,60min ≤ 100 dB(A) and keep the rest of the area more quiet to give the crowd the chance to rest and have a drink....

100dBA at exactly what distance?  If it's at 1m in front of the speakers you already have way more speakers than you need.
Title: Re: Midsized festival -> Line Array
Post by: Jelmer de Jong on December 27, 2013, 02:56:45 PM
100dBA at exactly what distance?  If it's at 1m in front of the speakers you already have way more speakers than you need.
The Belgium rules stated that de sound limit must be measured at a representative point in the venue. The next sentence in the document suggest the FOH position as a valid place to perform the measurement. This can be 10 feet from the stage if the room is barely 13 feet, this can also be 100 feet if the venue is 400 feet.

I suggest you keep using your current speakers, but place them higher and point them down. You get a lilttle bit more absorption from humans, a little less polution since the HF-drivers aren't blasting in the air and the relative difference in volume-level between front an back is reduced.
Title: Re: Midsized festival -> Line Array
Post by: Scott Stephens on December 27, 2013, 04:10:58 PM

Tijs,
 It looks to me that scaffolding would be a good thing for you to invest in.  A proper line array is outrageously priced and unless you have the money now to buy it, and the money later to recoup the cost; scaffolding is the way to go. Also, you may want to consider the extra insurance costs of putting something up in the air. Here in the states, insurance and the associated costs hurt the bottom line big time.
 Don't get caught up in the hype. A good point source system can cover a lot of ground as well as a line array. 
Just my 2cents. Good luck
scott
Title: Re: Midsized festival -> Line Array
Post by: Brian Jojade on December 27, 2013, 08:02:19 PM
It looks as though you are using JBL SRX725 top cabinets, 3 per side.  The dispersion of those cabinets is 75 degrees, so as deployed, you are going to have some significant overlap in coverage causing unpredictable results. 2 cabinets per side would probably result in better overall sound than 3, although it doesn't look as cool.

Still, those cabinets are going to offer you plenty of sound for a group of 1500 people, especially if you want it louder in the front and quieter in the back.  Raising up the cabinets a bit and tilting them down will help focus the maximum volume where you want it, right in the middle of the crowd.  It will reduce the amount of sound lost into space where only the birds can hear it.  I'd set scaffolding on the side of the stage and place the speakers there. This will give you a wider coverage pattern, and more stage front for the band to work with.

As far as investing in a line array, all that would do is put you in the kool kid group that has a line array, and cost you a ton of money.  One advantage that the line array does have is that each speaker in the array has a much narrower coverage pattern, so you can adjust the volumes of each speaker to get the desired volume where you want it.  Usually this would be used to balance the sound so that the speakers up high pointing to the back of the area are set higher than the ones pointing at the front row, much closer to the audience.  You've stated that this is the exact opposite of what you want.  Physics alone, with a single source cabinet is going to do what you want.
Title: Re: Midsized festival -> Line Array
Post by: Ray Aberle on December 27, 2013, 10:51:40 PM
Tijs,
 It looks to me that scaffolding would be a good thing for you to invest in.  A proper line array is outrageously priced and unless you have the money now to buy it, and the money later to recoup the cost; scaffolding is the way to go. Also, you may want to consider the extra insurance costs of putting something up in the air. Here in the states, insurance and the associated costs hurt the bottom line big time.
 Don't get caught up in the hype. A good point source system can cover a lot of ground as well as a line array. 
Just my 2cents. Good luck
scott
Hi Scott, Brian, if you noted the OP's second message, they are looking at hiring in a line array system, NOT purchasing. You guys are both right with the pricing involved with line array boxes... The initial investment plus storage, maintenance, upgrades, etc. as Tim would say, you need a "line," not a "dash."

To the OP, depending on what attendance levels you are looking at for this year... You SRX boxes may still work. I have a regular gig in Seattle each year I do with two 725s and three 728s per side, for dance music. Not the best, but it does the job and the client is happy.

Ray, "wants to buy some VerTecs this year" Aberle
Title: Re: Midsized festival -> Line Array
Post by: Brad Weber on December 28, 2013, 10:01:22 AM
I'm in the organising team of a midsized festival (1500pl) in Belgium, recently whe received new regulations that require us to redesign our audio setup. LAeq,60min ≤ 100 dB(A) is the new benchmark, currently our setup is very basic, woofers and speakers blasting the sound in the crowd.

We want to keep our sound level in front of the stage @  LAeq,60min ≤ 100 dB(A) and keep the rest of the area more quiet to give the crowd the chance to rest and have a drink.
Do you understand what LAeq(60mins) is and how it is measured?  Your levels will constantly vary, a Leq is the calculated equivalent continuous noise level those varying levels represent over the defined period, in this case one hour.  The addition of the "A" to LAeq also defines that it is to be A-weighted levels used.  Say you had 30 minutes at 120dBA and 30 minutes at 80dBA, that would represent a LAeq(60mins) of 100dBA.  Of course you levels will likely vary much more in both level and period so this is not a simple measurement and not something your typical entry level meter can handle.  It also means that the sound levels at any point in time may not result in an exceedance at that time but could contribute to an exceedance anytime in the next hour.

We have had numoures offers al presenting us a Line-array system. It is quite an investment but is it worth the money? What is your opinion? is it enough to just keep the current speakers and raise them of the floor or do we realy need the line array to give the crowd a desent sound quality?
Depending on the shape of the listener area, etc., a line array may help with directing more of the output at the listeners and less elsewhere, however it's probably not the approach you want if you want levels to drop off with distance.
Title: Re: Midsized festival -> Line Array
Post by: Tijs Proost on December 30, 2013, 03:58:06 AM
Yes,

I am familiar with the methods of measuring the sound.

We never had issious but in term of growing with the crowd and our local policy we are opting for line array.

Thx all for the reply's! If we find the correct sponsors to the finance the investmet we will be hanging line array. The other option will be suspending the current speakers in PA-towers.
Title: Re: Midsized festival -> Line Array
Post by: Josh Hana on December 30, 2013, 09:16:44 AM
I did a festival very similar in size to this a few months ago with 3 per side KF850s/SB850s and it worked out just fine. You shouldn't need to jump to a line array for something this size, especially when you already have perfectly fine boxes.
Title: Re: Midsized festival -> Line Array
Post by: Tim Weaver on December 30, 2013, 01:52:55 PM
In the effort of creating a louder space up front and a quieter space in the back, you are using the correct speakers right now. A line array's big party trick is to create LESS volume difference from the front to the back. In other words, a more even coverage from front row to back row.


If it were me, I would invest in a system to get those SRX cabs high up in the air and point them down at the crowd. If they don't have flypoints, then you are pretty much limited to using scaffolding and tie-down straps.

The good news, is that Vendors LOVE to pay you money to put their big logos up on scaffolding in front of the crowd!
Title: Re: Midsized festival -> Line Array
Post by: Bob Leonard on December 30, 2013, 02:32:44 PM
As an SRX owner I agree with all of the comments regarding the use of those boxes. The area you're covering isn't exactly a stadium by any stretch of the imagination and I'm sure if correctly deployed those SRX725s will do the job just fine. If the words line array meant something to your customer it might be worth renting a system for the day. However, when I look at the pictures you've posted it appears to be an early spring event which will surely draw a larger crowd if held during a warmer time of the year. Start drawing a crowd that won't fit into the area you show and then maybe an array would make sense.
Title: Re: Midsized festival -> Line Array
Post by: Spenser Hamilton on December 30, 2013, 04:29:05 PM
As an SRX owner I agree with all of the comments regarding the use of those boxes. The area you're covering isn't exactly a stadium by any stretch of the imagination and I'm sure if correctly deployed those SRX725s will do the job just fine. If the words line array meant something to your customer it might be worth renting a system for the day. However, when I look at the pictures you've posted it appears to be an early spring event which will surely draw a larger crowd if held during a warmer time of the year. Start drawing a crowd that won't fit into the area you show and then maybe an array would make sense.

+1, we've used our 725+728 rig for crowds way bigger than that with no issues (no blown drivers, etc). In one case, a crowd that was supposed to be 2-3,000 turned into almost 5,000, we certainly got to see what our rig was capable of that night, and the people who were standing outside the fence probably didn't get as nice of an experience as the people up front.
Title: Re: Midsized festival -> Line Array
Post by: g'bye, Dick Rees on December 30, 2013, 04:37:41 PM
As an SRX owner I agree with all of the comments regarding the use of those boxes. The area you're covering isn't exactly a stadium by any stretch of the imagination and I'm sure if correctly deployed those SRX725s will do the job just fine. If the words line array meant something to your customer it might be worth renting a system for the day. However, when I look at the pictures you've posted it appears to be an early spring event which will surely draw a larger crowd if held during a warmer time of the year. Start drawing a crowd that won't fit into the area you show and then maybe an array would make sense.

I'll "grump it up" a bit here and say that the rig you have PROPERLY DEPLOYED is more than enough for the job.  If you don't know how to make what you have work for you, then switching to a line array may or may not make for an improvement. 

It takes talent to make a line array rig NOT sound bad.  If you hire one, hire it delivered, deployed and tuned for you.  Anything short of that and you'll likely be spending more and getting less.
Title: Re: Midsized festival -> Line Array
Post by: Ivan Beaver on December 30, 2013, 05:36:31 PM
In the effort of creating a louder space up front and a quieter space in the back, you are using the correct speakers right now. A line array's big party trick is to create LESS volume difference from the front to the back. In other words, a more even coverage from front row to back row.


But that only works if the array is LARGE/LONG enough.  Most that are used in the size discussed are not long enough-except at the higher freq.

And when they are  not long enough-that means that the freq response from front to back will vary much more than a "point source" that drops equally in level across most of the freq band.

That is the thing that most people wanting/pushing line arrays seem to "forget" or ignore.
Title: Re: Midsized festival -> Line Array
Post by: Tracy Garner on December 30, 2013, 06:46:40 PM
In the effort of creating a louder space up front and a quieter space in the back, you are using the correct speakers right now. A line array's big party trick is to create LESS volume difference from the front to the back. In other words, a more even coverage from front row to back row.


If it were me, I would invest in a system to get those SRX cabs high up in the air and point them down at the crowd. If they don't have flypoints, then you are pretty much limited to using scaffolding and tie-down straps.

The good news, is that Vendors LOVE to pay you money to put their big logos up on scaffolding in front of the crowd!


I have an SRX rig. I'm interested in suggestions regarding a good method of tilting the 725 cabinets on scaffolding. I haven't seen many examples.
Title: Re: Midsized festival -> Line Array
Post by: Spenser Hamilton on December 30, 2013, 07:14:19 PM

I have an SRX rig. I'm interested in suggestions regarding a good method of tilting the 725 cabinets on scaffolding. I haven't seen many examples.

I don't understand why fly points were not standard on the SRX cabs...
Title: Re: Midsized festival -> Line Array
Post by: Tim McCulloch on December 30, 2013, 07:44:58 PM

That is the thing that most people wanting/pushing line arrays seem to "forget" or ignore.

My observation is that folks who screw up line array deployments also screwed up their 'point source' deployments.  Point sources are a bit more forgiving, but equally capable of sounding bad.  I'm not sure why we let flat pack, comb-filter builders off the hook and excoriate vertical nitwits.
Title: Re: Midsized festival -> Line Array
Post by: g'bye, Dick Rees on December 30, 2013, 07:49:46 PM
  I'm not sure why we let flat pack, comb-filter builders off the hook and excoriate vertical nitwits.

Names.  We need names...
Title: Re: Midsized festival -> Line Array
Post by: Peter Morris on December 30, 2013, 08:15:50 PM
Yes,

I am familiar with the methods of measuring the sound.

We never had issious but in term of growing with the crowd and our local policy we are opting for line array.

Thx all for the reply's! If we find the correct sponsors to the finance the investmet we will be hanging line array. The other option will be suspending the current speakers in PA-towers.

Hi Tijs,

From the way your new legislation is drafted it’s not aimed at dealing with environmental issues but to limit short term exposures that the audience receives to something sensible.

A line array is more likely to be able to achieve consistent dBA levels across your audience area than most point sources, even a relatively short line array. I suspect those people offering line arrays have told you the same.

I think you have made the correct decision – good luck organizing your festival.
Title: Re: Midsized festival -> Line Array
Post by: Peter Morris on December 30, 2013, 08:19:27 PM
Do you understand what LAeq(60mins) is and how it is measured?  Your levels will constantly vary, a Leq is the calculated equivalent continuous noise level those varying levels represent over the defined period, in this case one hour.  The addition of the "A" to LAeq also defines that it is to be A-weighted levels used.  Say you had 30 minutes at 120dBA and 30 minutes at 80dBA, that would represent a LAeq(60mins) of 100dBA.   Of course you levels will likely vary much more in both level and period so this is not a simple measurement and not something your typical entry level meter can handle.  It also means that the sound levels at any point in time may not result in an exceedance at that time but could contribute to an exceedance anytime in the next hour.
Depending on the shape of the listener area, etc., a line array may help with directing more of the output at the listeners and less elsewhere, however it's probably not the approach you want if you want levels to drop off with distance.

That’s not how you add Leqs!
 
eg. if 100 dBA = 100% dose then 103 dBA = 200% dose.
 
Note -  Leq assumes an Exchange Rate of 3 dB and applies to all ISO and British Standard measurements. In some Countries, for example the USA OSHA Standards use a 5 dB exchange rate.
Title: Re: Midsized festival -> Line Array
Post by: Ivan Beaver on December 30, 2013, 09:06:06 PM
My observation is that folks who screw up line array deployments also screwed up their 'point source' deployments.  Point sources are a bit more forgiving, but equally capable of sounding bad.  I'm not sure why we let flat pack, comb-filter builders off the hook and excoriate vertical nitwits.
I would not say that "flat front builders" are let off the hook.

I see people correcting them all the time.

Now what constitutes "flat front" may be up for debate.  Such as using 60° wide cabinets hard packed with the 15° angles flush.

"back in the day" there was a VERY POPULAR (and still used) trap cabinet that the "standard" usage was to always use an odd number of cabinets horizontally.  Then only use the ODD cabinets- (leave the even cabinets unplugged-or better yet shorted out).  The even cabinets were "spacers".

I built some arrays in EASE of both types of arrays (all on and even off).  The even off had much less interaction.
Title: Re: Midsized festival -> Line Array
Post by: Ivan Beaver on December 30, 2013, 09:14:05 PM


A line array is more likely to be able to achieve consistent dBA levels across your audience area than most point sources, even a relatively short line array. I suspect those people offering line arrays have told you the same.


It depends on what you consider "short" and "even".

For example a 5' tall array (that is longer than many "short" arrays) will only exhibit the "line array" effect (3dB/doubling of distance) for about 5'.

If you go up to 1Khz it goes out to about 10' and down to 250Hz it is about 2.5'.

After that distance it will drop off at 6dB/doubling of distance-just like a "point source".

  So since most people are at least 10' away-they get the same losses.

It takes a lot longer array (ie more boxes) to get the "effect" people "think" they are getting.

But that doesn't stop them from "thinking" their system is doing something it is not.
Title: Re: Midsized festival -> Line Array
Post by: Peter Morris on December 30, 2013, 10:12:04 PM
It depends on what you consider "short" and "even".

For example a 5' tall array (that is longer than many "short" arrays) will only exhibit the "line array" effect (3dB/doubling of distance) for about 5'.

If you go up to 1Khz it goes out to about 10' and down to 250Hz it is about 2.5'.

After that distance it will drop off at 6dB/doubling of distance-just like a "point source".

  So since most people are at least 10' away-they get the same losses.

It takes a lot longer array (ie more boxes) to get the "effect" people "think" they are getting.

But that doesn't stop them from "thinking" their system is doing something it is not.

Yes I know, but in this case the compromise we are talking about is meeting a legislative requirement which is measure in dBA. The low end is not really important to the measurement.

The other thing to note is people tend to use multiple point sources with overlapping patterns.  The point source performance of such a system will not come close to matching something like one of your Jericho horns despite have a similar number of drivers.

While I would love some Jericho horns they are not practical for a hire company like mine and many others.  From my experience I think the best you will do in this case is a medium sized line array. If the festival has the budget, a Martin MLC would be the go.
Title: Re: Midsized festival -> Line Array
Post by: Bob Leonard on December 30, 2013, 11:46:48 PM
The little white tent would appear to be 12' long and it also appears that is where FOH is located. Some quick scaling puts FOH about 40' from the stage and the back of the venue at about 100'. You're saying that a line array is needed for that distance? OK, so now that the array is in place what's being used to cover the giant gap up near the front of the stage? I've done public concerts using a pair of SRX725s per side for 1500 people in similar or even larger outdoor locations with better coverage up front, and can hit just under 100db at 75' without pushing them too hard at all. Strawberries to the hogs I say.
 
OP,
It appears your mind is made up at this point. Let us know how you make out with the array, and good luck with your concert.
Title: Re: Midsized festival -> Line Array
Post by: Tim Weaver on December 31, 2013, 02:38:28 AM

I have an SRX rig. I'm interested in suggestions regarding a good method of tilting the 725 cabinets on scaffolding. I haven't seen many examples.


It's not that hard. Build a tilt board with the amount of tilt you need. Strap the board to the scaff, and strap the speakers to the board.
Title: Re: Midsized festival -> Line Array
Post by: Bob Leonard on December 31, 2013, 07:47:23 AM
I don't understand why fly points were not standard on the SRX cabs...

Fly points are an option at time of purchase.
Title: Re: Midsized festival -> Line Array
Post by: Stu McDoniel on December 31, 2013, 03:33:27 PM
Hi all,

I'm in the organising team of a midsized festival (1500pl) in Belgium, recently whe received new regulations that require us to redesign our audio setup. LAeq,60min ≤ 100 dB(A) is the new benchmark, currently our setup is very basic, woofers and speakers blasting the sound in the crowd.

We want to keep our sound level in front of the stage @  LAeq,60min ≤ 100 dB(A) and keep the rest of the area more quiet to give the crowd the chance to rest and have a drink.

We have had numoures offers al presenting us a Line-array system. It is quite an investment but is it worth the money? What is your opinion? is it enough to just keep the current speakers and raise them of the floor or do we realy need the line array to give the crowd a desent sound quality?
A few ideas

Use the system you have.

Splay your tops more to minimize overlap.

Get those tops higher up in the air.

The recommendation of scaffolding is a good one.

Keep it simple.
Title: Re: Midsized festival -> Line Array
Post by: Brad Weber on January 01, 2014, 12:41:07 PM
That’s not how you add Leqs!
 
eg. if 100 dBA = 100% dose then 103 dBA = 200% dose.
 
Note -  Leq assumes an Exchange Rate of 3 dB and applies to all ISO and British Standard measurements. In some Countries, for example the USA OSHA Standards use a 5 dB exchange rate.
From varous sources the Leq is:
  I was not adding Leq values, rather showing a simplistic example of a one hour Leq consisting of two 30 minute periods with different levels.  To actually measure Leq or LAeq you genherally use an integrating sound level meter.  It integrates the levels (energy) measured over the defined time period and then divides that total value by the overall time period to determine the average or continuous equivaleant level over that period.
 
Dose relates to OSHA, ISO, etc. and where the Exchange Rate referenced relates a Leq or TWA to the related defined 8 hour Dose.   That is alsdo why those situtation are best approached through the use of dosimeters for any measurements.  However, there are numerous community, environmental and other noise guidelines and measurements that use Leq and/or TWA measurements, as well as other defined descriptors such as Ldn, Ln, etc., without any relation to OSHA, ISO, etc. or to the related Dose.
Title: Re: Midsized festival -> Line Array
Post by: Lee Buckalew on January 01, 2014, 01:37:57 PM
Hi all,

I'm in the organising team of a midsized festival (1500pl) in Belgium, recently whe received new regulations that require us to redesign our audio setup. LAeq,60min ≤ 100 dB(A) is the new benchmark, currently our setup is very basic, woofers and speakers blasting the sound in the crowd.

We want to keep our sound level in front of the stage @  LAeq,60min ≤ 100 dB(A) and keep the rest of the area more quiet to give the crowd the chance to rest and have a drink.

We have had numoures offers al presenting us a Line-array system. It is quite an investment but is it worth the money? What is your opinion? is it enough to just keep the current speakers and raise them of the floor or do we realy need the line array to give the crowd a desent sound quality?

For your existing gear the suggestions of getting it up in the air and angles down are excellent.  It may mean using a pair each side up high angles down and the other two cabinets used as front fill either from the stage or from a slightly lower level on the scaffold.  Angle for appropriate coverage.  You should be able to provide much more even coverage and also limit some of the spill.

If you are wanting to hire in a system to see what can be done in a different way I would encourage you to check out the Martin MLA-C (for this size area the MLA would be overkill) system for its ability to control the evenness of coverage within the listening area and to limit SPL outside of the coverage area.

Lee
Title: Re: Midsized festival -> Line Array
Post by: Ivan Beaver on January 01, 2014, 02:15:16 PM
For your existing gear the suggestions of getting it up in the air and angles down are excellent.  It may mean using a pair each side up high angles down and the other two cabinets used as front fill either from the stage or from a slightly lower level on the scaffold.  Angle for appropriate coverage.  You should be able to provide much more even coverage and also limit some of the spill.

If you are wanting to hire in a system to see what can be done in a different way I would encourage you to check out the Martin MLA-C (for this size area the MLA would be overkill) system for its ability to control the evenness of coverage within the listening area and to limit SPL outside of the coverage area.

Lee
But if I was reading it right-the SPL limit was to be measured WITHIN the coverage area-kinda specifically the FOH position.

So it appears they are not so concerned with the spillage, but rather the SPL exposure of the people in attendance.

QUITE a different thing than trying to not annoy the neighbors.

Unless they put FOH outside the coverage area-but we don't want to go there.
Title: Re: Midsized festival -> Line Array
Post by: Lee Buckalew on January 01, 2014, 02:33:45 PM
But if I was reading it right-the SPL limit was to be measured WITHIN the coverage area-kinda specifically the FOH position.

So it appears they are not so concerned with the spillage, but rather the SPL exposure of the people in attendance.

QUITE a different thing than trying to not annoy the neighbors.

Unless they put FOH outside the coverage area-but we don't want to go there.

Yes, the new regs posted are about audience area but, unless this is very different from many other areas around Europe there are existing strict limitations for spill as well.  Perhaps not.
Either way they can get more even coverage with their existing system with many of the suggestions provided or, if they want to hire in a system just to try it out, they can get exceptionally even coverage throughout the listening area with any of the MLA variants plus realize the added benefit of better control over off-site spill and better control of bleed on the stage.

Lee
Title: Re: Midsized festival -> Line Array
Post by: Peter Morris on January 01, 2014, 08:07:25 PM
For your existing gear the suggestions of getting it up in the air and angles down are excellent.  It may mean using a pair each side up high angles down and the other two cabinets used as front fill either from the stage or from a slightly lower level on the scaffold.  Angle for appropriate coverage.  You should be able to provide much more even coverage and also limit some of the spill.

If you are wanting to hire in a system to see what can be done in a different way I would encourage you to check out the Martin MLA-C (for this size area the MLA would be overkill) system for its ability to control the evenness of coverage within the listening area and to limit SPL outside of the coverage area.
Lee

+1 ... I’ve been lucky enough to have a play with MLC … its sound quality and ability to maintain even coverage and control SPLs outside the listening area is fantastic.
Title: Re: Midsized festival -> Line Array
Post by: Peter Morris on January 01, 2014, 08:36:35 PM
From varous sources the Leq is:
 
  • Equivalent continuous A-weighted sound pressure level is widely used around the world as an index for noise. It is defined as "the A-weighted sound pressure level of a noise fluctuating over a period of time, expressed as the amount of average energy."
  • The average sound level measurement over the run time.
  • The Equivalent Continuous Sound Level is the preferred single decibel value to describe Sound Levels that vary over time and would produce the same Sound Energy over the same period of time T.
I was not adding Leq values, rather showing a simplistic example of a one hour Leq consisting of two 30 minute periods with different levels.  To actually measure Leq or LAeq you genherally use an integrating sound level meter.  It integrates the levels (energy) measured over the defined time period and then divides that total value by the overall time period to determine the average or continuous equivaleant level over that period.
 
Dose relates to OSHA, ISO, etc. and where the Exchange Rate referenced relates a Leq or TWA to the related defined 8 hour Dose.   That is alsdo why those situtation are best approached through the use of dosimeters for any measurements.  However, there are numerous community, environmental and other noise guidelines and measurements that use Leq and/or TWA measurements, as well as other defined descriptors such as Ldn, Ln, etc., without any relation to OSHA, ISO, etc. or to the related Dose.

 :-\ well you did say ..."Say you had 30 minutes at 120dBA and 30 minutes at 80dBA, that would represent a LAeq(60mins) of 100dBA."