Automatic power shutdown of noise

[DBA]

One of my local pubs has a traffic light system that cuts the power to the sockets when it gets too noisy for more than 10 seconds. The bands are forced to plug into these sockets and are very unhappy about the brownouts to PAs and valve amps. Although the music can be loud some of the swamp dragons shrieking can cause the power to be cut. Two bands so far have walked out complaining that its not rock n roll !!

 

Does anyone know what this traffic system is actually called?

 

Is it safe for the band with their power being disrupted?

 

Is this the way things are going where live music is muted due to the Noise Regulations?

 

Thanks in advance.

[dbuckley]

Does anyone know what this traffic system is actually called?

Likely to be either from Formula Sound or from Castle Electronics, the Electric Orange

 

Unpleasent tools. Some equipment is less tolerant than others of power removal, possibly the worse offender being the otherwise excellent Driverack PA. When it loses power it shows its ingratitude by blowing drivers. So a decent PA with a DRPA would not last past the first dragon's call...

 

UPS for the PA, Sir?

[Light Console]

Perhaps someone could design a box with a heap of relays/contactors inside wired to the output of the limiter. Rest of stage is supplied with constant power, but every signal cable for back-line or speaker cable for main PA/monitors goes through the relay box, thus only killing the speakers not the amps/rack running it.

 

Edit, just thought of another way to do it. It will only work with the mixer inputs and not back line. Wire up a load of insert leads into aforementioned relay box. With the relays in working mode, the connect Tip with Ring, in non working mode (ie level exceeded) connect Tip to Screen. I made a similar type box for a local Church, when their desk didn't have mute switches, but they had need of switching off 8 mics and switching on 2 others at the same time. Even with 10 mics changing, there is no Bang heard.

[robloxley]

All the devices that simply cut power are a bit crude.

If you have a venue PA then something like the FORMULA SOUND AVC2 limiter is a bit more sophisticated.

[Seano]

every signal cable for back-line or speaker cable for main PA/monitors goes through the relay box

Bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz!

(This is the sound of the box of relays.)

:)

[Light Console]

Bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz!

(This is the sound of the box of relays.)

:)

Fair point, well presented. I guess I was thinking of relays that are normally closed, ie need electricity to disconnect the signal. As the power gets turned off...ah well back to the drawing board, or should that be CAD Tablet?!

[Andrew C]

Bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz!

(This is the sound of the box of relays.)

Why? Use DC coils, no reason why a well designed system couldn't work.

 

However, it would be much too easy to bypass in the real world. These systems are designed to protect performers, staff & audience from dangerous levels, and neighbours from noise pollution.

 

They way to avoid them tripping is to moderate the use of the loud button!

[MarkPAman]

OK

 

I hate these devices. Had to work with (or against) one last week and will do again next week.

 

The thing is though that as Andrew says, there is a good reason for them to be there. Just asking bands to keep the volume down, unfortunately, doesn't often work. Long term, it makes no sense for a venue to loose its licence due to noise complaints just because a band "need" to play at volume.......Can I say "lack the talent to keep it down"? :)

 

In the case of the band I was working with, it was mostly the guitar amps wot done it.

 

As suggested earlier, better methods are possible for a fixed system, but even the band's backline can be too loud and these power tripping systems are about the only foolproof method - when properly installed.

 

H&S sets (IMO) pretty low SPL levels already & we have only a couple of years before we will have to make further reductions. As I now seem to have been volunteered to be the one at work who checks sound exposure, I suspect that I will soon be getting some of these fitted in our rehearsal rooms. I don't want to, it will not make me popular. It should stop me and my employers getting sued.

 

In the mean time I'll be back to the pub with the system fitted. This time I'll be asking very nicely for a power socket for my digital desk as it didn't take kindly to being turned off and on this way and refused to turn on for about 2 (very long) minuets (the Behringer,that is, the Mackie fires up in about 2 seconds). I will also be wondering why it is on the back wall of the stage where the band can't see it but the audience can. <_<

[paulears]

While agreeing they are pretty terrible things, most venues who have them have been MADE to have them by the licensing authorities. Pub bands being what they are have a single guitar stack that can trip the system without anything else. This fact, plus the PA simply being for getting vocals over the guitars and drums means sounds levels out of control. Very often nobody really mixing, just fighting back line. Even pulling the PA faders down won't stop the warning light goes to red and then silence. NOT the fault of the gadget - it is doing wat it was designed to. Pull the power. All the cleverness in the world won't make it work - with bands like this brutal is the only way they learn - and then, they spend ages trying to work around the system - the result being simply that they want to be too loud for the venue.

 

I have not got one jot of sympathy for them. 2000 watts of pure distortion comes to mind. If you have a PA that gets damaged by cutting the power, then I'd say it was too large for venues with this kind of device fitted - after all, bigger venues tend to have decent power supplies that rarely are linked to sound levels - my experience of the things is in the pubby-clubby venues - often near housing where people sleep!

 

Most MI PA products, rather than pro products are pretty bomb proof when it comes to cutting the power - a designed in feature maybe?

[Stewart Newlands]

I have been in venues with power cut off limiters that cut on an acoustic share drum and can be set off by vocal cheers!

 

Getting the LA officer to set limits can take time they sometimes set them in a big empty space before you pack it full of people, you need 10DB over the ambient noise to have any PA worth using IMO.

 

One venue local to me has this type of system on the 63A 3Phase - and that is nasty cutting in and out on full load.

 

It is only the output stage that are required to be limited, your desk, outboard drive rack etc don't cause an issue without amps.

 

 

I always find it good when the band are happy to work with you to get the levels right at sound check, be it that the back line could be louder than the PA in a pub or the stage noise levels are such that the crew want ear defenders, plugs and a day off to cut noise exposure on a large stage! (I have even used talking books on CD to give bands a vocal level to set the back line levels by.)

[Light Console]

I used to work in a venue with an Electric Orange. I don't recall ever tripping it during a live gig. I do recall the odd trip whilst doing sound checks though. When I was decommissioning the venue, I found a 10dB pad in line with the mic!

 

During my Thomson days, many hotels in Spain with outside entertainment have to be fitted with sound limiters. This normally consists of a mic somewhere on the terrace, which of course, pics up audience applause. This then reduces the output of the system. Somewhere in the region of 60dB at the perimiter of the hotel is the max limit. Two years before I worked in a hotel, the outside venue was closed by the police, and the sound kit removed when they exceeded the limits. They then had to build a million Peseta venue, with inch thick glass to keep the sound in. They then installed a 2kw Mackie sound system, which I was able to run at 100dB inside and not a squeak at the perimiter fence! As part of the rules, there was a sound limiter installed and operating, which was time controlled, but I think it never affected the sound.

[Ellis]

I have crewed in a venue with the Formula Sound Sentry, but it was switched off for the particular operatic society because they could trigger it without amplification (and sudden black-outs were considered dangerous!)

[andy_s]

I have crewed in a venue with the Formula Sound Sentry, but it was switched off for the particular operatic society because they could trigger it without amplification (and sudden black-outs were considered dangerous!)

 

why would cutting the sound power supply lead to a sudden blackout?

 

(but Opera singers can make a very loud noise - I saw Rosalind Plowright singing at the Buxton Opera Festival years ago and came out with my ears ringing as if I'd been at a Dr Feelgood gig)

[Ellis]

I have crewed in a venue with the Formula Sound Sentry, but it was switched off for the particular operatic society because they could trigger it without amplification (and sudden black-outs were considered dangerous!)

 

why would cutting the sound power supply lead to a sudden blackout?

 

 

 

When everything connected to the power DB was cut by the bloody thing (including the dimmer supply and the 63A sockets)!

[andy_s]

When everything connected to the power DB was cut by the bloody thing (including the dimmer supply and the 63A sockets)!

hmm yes I agree - if you save someone from one peril only to expose them to another equal or worse danger, then something's not quite right.....