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Post by soundmanjim on Feb 21, 2007 1:46:29 GMT 1
Hi all
more questions.
looks like we will be having our regular Horndon live music festival again this year (just got back from the meeting) BUT it looks like we have a neighbour to contend with.
We were advised by the local council planning guy to fire the speakers away from the village and aim into the countryside - away from the back of the pub. (gig held in pub car park).
Trouble is, one neighbour lives there and he wasn't best pleased at having his living room windows jiggled by high levels of Blues/rock. Bless.
Anyhoo, there could/will be an issue with him this year so i suggested rotating the stage back towards the pub and the village BUT reducing the pa to a more sober level - we used 8 HK subs and 4 HK mid tops (all actor system) last year - so im intending to use just 4 active subs and two EV mid tops powered via qsc amp.
What i really want to know, is there any way i can prevent any spill from the back of the stage in the direction of our angry neighbour? he lives about 200 yards away from where the back of the stage will be - my main concern is spill from the monitors and the drum kit on the riser.
any ideas?
the back of the stage is usually tarped off but that really doesn't do much to the sound.
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Post by John Bell on Feb 21, 2007 13:50:45 GMT 1
Hi Jim, You could always offer to gaffer tape his windows and clean them afterwards. Or maybe you could pass a bucket arround and offer to pay for a night out of town. Another option would be to borrow a JCB and build a sound barrier out of earth, similar to the one's the council's use to protect new housing estates from traffic noise.
Best of luck, John.
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Simon Ryder
Boss
Bringing out the best through sound
Posts: 212
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Post by Simon Ryder on Feb 22, 2007 2:53:38 GMT 1
Hmm, not much you can do about spill from the monitors. If it is the bass he is worried about you could always build a directional bass array. Hard to make a recommendation though as to which method to use and which way to aim it without seeing the site.
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Post by soundmanjim on Feb 22, 2007 11:49:47 GMT 1
...or i could just turn the volume down.
pacification techniques were employing this year include
free tickets for gig / beer on us for him / mention him in the advertising.
i think his main issue was the fact that the stage was facing right at him. he had said originally that he was going on holiday that weekend and that it wouldn't be a problem - then he changed his mind.
one idea is to borrow a sound level meter during sound check and go stand behind the stage and make some measurements - and make sure he can see me doing it!
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Post by gingerbiscuit69 on Feb 24, 2007 15:15:12 GMT 1
if you can get hold of some old carpets, hang them off the back like the tarp would be. that will kill most treble, a lot of mid, and the bass really cant be helped!
using the reflex subs, make sure they are on the floor (or within 3") so they couple with the floor, this will allow you to achieve a louder sound in the audiences area yet playing them quieter than before, which also helps keep distortion down and gives them an easier time.
how large is the area you are covering? having delays will help cut down the volume needed FOH.
could also do what glasto did .... LOAD AND LOADS of wireless headphone haha!
if the neighbour isnt too much of a stressy bugger, how about perspex sheets covering the windows on the side of the house thats exposed? having a layer of air inbetween two surfaces is the most effective way of killing sound (sound is waves, its good at sucking energy out of them). when we have overkill house parties/raves, we stick bubble wrap layers an inch or so away from the window pane, put matresses up against them ect.... very very effective!
if all else fails, hit the black market and get some GHB, and knock him out for the weekend, he wont remember a thing when he wakes up... lol!!
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Post by soundmanjim on Feb 25, 2007 0:57:17 GMT 1
ROFL. great idea.
Yes, subs on the deck would be better, can bung em under the stage out of the rain (its BOUND to rain in July)
i was going to ask about delays - ive got that control on the x-over - the car park is about 60 feet long by about 30 wide - how do i set the delays?
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Post by gingerbiscuit69 on Feb 25, 2007 12:59:33 GMT 1
easiest way is to blag it by ear, just delay the delays until they are in line with the FOH.
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Simon Ryder
Boss
Bringing out the best through sound
Posts: 212
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Post by Simon Ryder on Feb 25, 2007 20:55:58 GMT 1
Measure the distance from your left stack to the left delay. Simplest way to set the delay is 1 foot per millisecond.
Most accurate way is to do the equation: Speed = distance / time
or in this case:
time = distance / speed
You can take the speed as being 344 m/s (depending on temperature of course) If you for example have a distance between your FOH stack on the left and your left delay of 10m
then; 10/344 = 0.02907 seconds or 29 milliseconds
Your delay at 20 degrees C at 10m would therefore be 29 ms
To work out the actual speed of sound on the day itself take a thermometer and a calculator.
The equation is:
C = 331 + 0.6 * T
C = the speed of sound T = the temperature.
then feed that answer into:
C=D*T
D= distance T = time
Then do the same for your right stack and delay.
Mostly I just use the 1 millisecond per foot rule of thumb and pace it. (my feet are a foot long)
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Post by soundmanjim on Feb 26, 2007 0:04:45 GMT 1
you lost me at left stack to left delay. what left delay?
no idea.
havent a clue.
need this in idiot speak please!
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Post by John Bell on Feb 26, 2007 10:30:16 GMT 1
The left and right delays are the additional FOH type cabs that are placed, (in the example), 10m from the front of the stage, into the audience area, that have to be time delayed to allow the sound from the stage stacks to catch up with them. This prevents the typical train station announcement effect. The delay cabs can now give the back end of the audience a good sound level, without having to blast the FOH cabs. John.
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shepz
Senior Engineer
Posts: 135
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Post by shepz on Feb 26, 2007 12:05:22 GMT 1
Give the neighbour some [moderator] - he won't make a single complaint =]
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Post by soundmanjim on Feb 26, 2007 16:23:44 GMT 1
ah. wont be using any extra cabs, costing me enough for the ones im getting. only using a pair of foh stacks, the car park isnt that big really.
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Simon Ryder
Boss
Bringing out the best through sound
Posts: 212
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Post by Simon Ryder on Feb 26, 2007 22:18:27 GMT 1
Sorry Jim, I guess I was answering a different question than you were asking.
Were you asking how to time align your subs with your mid highs if the subs are under the stage and the mid highs are in front of it?
If so its the same rule as above.
Take whichever is furthest back, measure from the driver of the sub to the driver of the mid high. Delay whichever one is further forward by 1 milliseciond per foot.
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Post by soundmanjim on Feb 27, 2007 0:04:45 GMT 1
yes, sort of! more than anything wondered what the delay adjustment did! thanks all the same. :-)
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Simon Ryder
Boss
Bringing out the best through sound
Posts: 212
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Post by Simon Ryder on Feb 27, 2007 16:35:22 GMT 1
The delay adjustment allows you to align in time (distance) different components of a pa system.
If you look at a conventional 15" and 2" horn active (by which I mean an active crossover is required and 1 amp channel per driver NOT a powered cabinet) cabinet, the diaphragm of the 2" horn is significantly further back in the cabinet than the diaphragml of the 15" driver. This means that sound will reach you first from the 15"driver with the sound from the horn lagging slightly behind. This will result in an unnaturally bass heavy sound with a great deal of smearing (time based distortion) around the crossover point. If you delay the 15" driver so it sounds at the same time as the 2" horn, you will get a much truer representation of the signal going into the speaker. You may well also find that you need less EQ as well.
It is pointless trying to EQ a system that is not time aligned as you are trying to correct something that is a timing based error with a frequency based corrective tool. You may get it sounding good enough that way, but it will never sound as good as a system that has been time aligned correctly and then EQ'd
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