Audio cut off

[Jfa]

Hi,

 

Can anyone tell me where the best place to get an install audio power cut off device would be?

 

Cheers

[pete10uk]

Hi There.

 

I think in order to get any kind of response, you will need to describe what you are after in more detail.

 

If you say what is your issue and what you would like to cut the power off to, would give us an idea.

[Simon Lewis]

Are you refering to something like this?

 

http://www.formula-sound.com/images/products/sentry/sentry.png

 

 

[mutley]

If you mean a device to cut all audio when the fire alarm sounds, there are various ways you could do this, and many commercial solutions cut the audio, but NOT the power, allowing you to have a system for making emergency announcements if necessary:

 

At the UK holiday resort I worked at, we used an Allen & Heath DR128 zoner which has a 9-way D connector on the back to interface to your fire alarm system. Not cheap!....

 

The cheapest option would be a simple 4 pole relay, which connects the output of the desk to the amps. If you use a changeover (4PDT) relay, you could then use the switch-over contacts for the input from your emergency PA. (ie; if there's a fire in the foyer, you might want to advise people to evacuate via the side doors only....)

With a bit of thought, you could even use the INSERT sockets on the main output of the desk, to cut most audio, but switch over to an AUX output for use as an emergency PA, which will then also be transmitted via the induction loop as well......

[Jfa]

Are you refering to something like this?

 

http://www.formula-sound.com/images/products/sentry/sentry.png

 

 

Yeah that's what I need. Any idea on price? I need to link it to my music power so when its to loud power cuts.

[Simon Lewis]

There's a page full of the blighters here. There may well be other distributors, so try Googling. You can buy standalone versions that just plug in - but of course it's dead easy to bypass via a non-controlled socket, and you are limited to the 13A that can be drawn from a single plug,

 

The larger ones require some form of wiring in, and, if you need to switch higher currents, would need a contactor as well. If you are not competent to install and test, then you'll need an electrician to do this.

 

The other issue is setting the level that it warns / trips at. The fact that you need one of these devices suggests someone (local council?) has received noice complaints and is trying to control noise levels by use of a mains cut off unit. If so, they will want to know that the trip level has been correctly set, and that the microphone / set level can't be knobbled easily. They may need to be involved at the commissioning stage.

 

Hope this helps,

 

Simon

[pete10uk]

Once upon a time I lost 2 speakers and an amp due to a unit looking very similar to the one pictured. A nice party gig with loud music, just as it got warmed up BANG! Bye bye speakers and one channel of the amp.

 

I don't plug anything in to them anymore.

A long extension normally solves the problem.

 

Now if I see the 3 red light I you know it need to turning down a bit. I have also plugged in my desk light in to it and if that goes off I also need to turn it down a bit.

[callumb]

Those things are the spawn of satan him self! There are far better methods of noise control out there!

[mutley]

Have a word with your local Council Environmental Officer (or whatever title they give themselves) to discuss your options.

 

As pete10uk said above, cutting the power to a "pumping" PA is not ideal as it can cause damage. Offer to self-regulate by using a calibrated noise level meter, and say that any official representative is welcome to come along and check noise levels at any time. It also depends on your building, just how much noise you will be able to make: a tent has virtually no sound deadening to it, but an underground nightclub has a lot!

 

A lot of officials use an "attitude test" - fail this and they'll be as awkward and difficult as they can be; if you approach them pro-actively, and offer to work with them to make sure the local residents are happy as well as your punters, they will normally accept that you are acting responsibly, and allow you to self-regulate your noise levels.

 

When I worked at a UK holiday park, we had to take three noise meter readings each evening (any time after 6pm), and record these in an official log. Sometimes management would do their own as well, just to check.

 

The other option might be to install a limiter, maybe at the back of the rack and put security screws in the rest of the gear to prevent unauthorised access (meddling).

[audiomik]

Worth looking at the Drawmer SP2120 Speaker Protector which quotes it's use as:

"The unit also gives a wide variety of venues, such as clubs, theatres, pubs, schools, universities etc. the opportunity to comply with the local legislation regarding noise levels."

 

Info here: SP1210

 

There is another type of System Limiter which has a negative gain slope above a set threshold, but can't remember which unit this is.:unsure:

Advantage of this one though is if the 'operator/DJ etc' drives the system over the threshold level then the SPL of the system drops......

 

The important bit with either of these devices is that the EHO can be satisfied that Sound Levels will be properly controlled whilst there isn't any potential for damage to Amplifiers/'speakers due to power interruption.

 

Both good for installed systems, but for venues which have different systems brought in for events then you may be down to the switching units. It's not clear which situation this thread refers to.

Mik

[Simon Lewis]

There are problems with all of these approaches, and whilst I would certainly recommend a proactive and helpful stance with the local EHOs, in many cases they are jaded and weary of bands and discos causing noise complaints. They can understandably default to the opinion that we are the problem...

Having said that, a good EHO should balance the need for minimising environmental impact with the right for business and entertainment to take place and flourish.

 

A few thoughts...

 

The noise limiter "solution" is usually an attempt to limit noise without having to send an EHO out to monitor levels every 5 minutes.

 

The degree of noise nuisance experienced at the (nearest) noise sensitive property may vary by the degree of leakage from the venue (so a basement club with large air vents could be just as problematic), the time of day, number of occurences, spectral distribution and even musical style.

 

 

Devices that turn off the mains can be set incorrectly, are hated by users (especially if they turn back on automatically or by an unsuspecting bar steward). It is easy to run part of the sound system or backline from an extension lead that isn't controlled by this box. Many have the measurement mic covered in gaffer tape...

 

Devices that limit the signal to the FOH amps are good, but in a larger system you'd need multiple units for monitors, and of course backline amps can be louder than the PA. I have seen such limiters very quickly defeated by visiting DJs or engineers gaining access to the amp rack and simply connecting the I/p and o/p XLRs together.

 

It's quite possible to not trigger an electronic orange (set to A weighting) and still get complaints if you play back very low frequency material.

 

In my opinion, places that wish to have loud music playing need to assess a range of factors including noise isolation, control of sound pressure level and the aural safety of their staff.

[Brian]

How about a Sentry type unit that turns on all the houselights, maybe augmented by some extra halogen floods, when it gets too loud? No band or DJ will wants to kill the atmosphere.

[J Pearce]

Automatic blinders! Sounds a good idea to me :P

[Jivemaster]

If you need one of those either the venue is unfit for events or you are unfit to supervise the sound there (or both!).

 

The problem of noise needs a solution but cutting the sound and the disco lights will produce H&S issues with a room full of drunks in the dark. You really should be looking at the SOURCE of the sound first, Don't make the noise, Once you accept a band or DJ you have to accept that it will be loud.

[weedkiller]

Playing at a wedding earlier this year, newish venue. B&G were introduced for first dance, audience cheered wildly and loud (as encouraged to do). Limiter cut off the power before I even started playing. Had to run and get extension leads to take power from different sockets. I saw the lights going red but couldn't believe it. Embarassing and out of my control. Bar manager said no-one uses those (stage) sockets! I was very tempted to use large hammer to make sure.

WK