Sound level cutoff meter

[stuee]

LittleGhostman. Thanks for your input, i understand what you think works but in the real world it doesnt . The venue is only for upto 50 people, no matter how much you tell them they always have to go over after intoxication starts, There will also be a sign saying that if the music is over a certain limit then it will auto cut off, people always push as far as they can and when you work out that it cuts out wont keep trying. As for staff the venue is a private function room and costs $300-400 for the night and requires no staff, if i was to put staff on it would cost me around $200 the night.
I did look at the commercial ones and for the sake of what it is they are very pricey.

RELOADRON: I dont have a scope but like i said i was aiming at putting a car 12v relay inline on the + line out to the active speaker then when it triggers to turn off sends the current to the relay and disconnects? Im sure the standard line voltage is around 1v

AUDIOGURU: Yes mate im in Australia but... I am originally from the UK 12 years ago

TOMIZETT: It wouldn't get to a lawyers stage, just moaning neighbor businesses.

 

[KeepItSimpleStupid]

The really hard part, is location, location and location. Like where do you put it? Inside the 'active speaker'? Wirelessly commanded?

When the "stage power" is integrated into the building and sound monitoring, you have a chance. Hopefully, someone won;t find a a 500' extension cord or get power from a generator.

 

[stuee]

well theoretically this is just a small circuit as i put at the start, the microphone sensing the noise will be across the other side of the room an a suitable area with the wire running back )20m) to the circuit which only need the leds visible so they can see they are pushing their luck by the orange and red lights flicking and turn down and if the dont well it will then send a 12v signal to the relays and disable the audio.

In my head this sounded quite simple but not sure why its turning into something so hard.???

As mentioned in the first post.
Led bar via microphone sensor >when the red lights are activated for longer than 5 (variable) seconds it then send a signal to another timer that then sends 12v to the the relays for a certain time (variable) then the music come back on.

 

[alec_t]

You'll need to conceal the mike (assuming its only purpose is for the cut-off), otherwise some clever so-and-so will simply muffle it and hence raise the sound level .

 

[stuee]

Yeah alec-t i thought about that too lol, i do have a spot but think it will be trial and error!

 

[audioguru]

Trial and terror?

 

[KeepItSimpleStupid]

The basis is the average detector with a mic, log scale.
1st. question: One or 2 bars - or is cascading necessary?
2nd. Question:
I might consider using optos for the LED's which means running the OPTOs so they always work. They can be interfaced to your comparitor circuitry AND another LED which has PWM or something else for a brightness control.

You can base your threshold on nothing but gain. Above and below some line.

So,using the internal brightness control is A problem.

==

To SIMLIFY your comparitor, you only have to use one LED. The one past the threshold.

This is where analog wizidry might be better replaced by digital wizzardry. e.g A PICAXE www.picaxe.com.

Brightness based on light levels MAY be an option.

There is no "real difference" having the display in the room facing opposite the audience. It's just bigger.

Wireless control of your relay with a battery inside the measuring gizmo is certainly an option. Running mic wires long distances could be problematic.

So, anyway, I'm still suggesting:
1. Microphone based
2. Average responding
3. Log bar graph drive
4. One or two cascaded?
5. Replace all the LEDs in the bar graph driver with optoisolators.
6. Drive the LEDS from the OPTO interface.
7. duplicate brightness control
8. Use the threshold LED as the basis for the alarm circuitry.

 

[stuee]

Thanks for the input thus far.
how would i make a timer circuit with variable timing from one sec to say 20 seconds, also how would i get that to output a trigger to the next time which will make that turn send the pulse to the relays a variable time (30 secs - 5mins) ?

 

[stuee]

I have found this kit which should do my sensor / vu meter needs, now just to make the timer circuits
**broken link removed**

 

[stuee]

i have now just purchased this too https://www.amazon.co.uk/Channel-Relay-Module-Shield-Arduino/dp/B00INX6CMQ
5v relay which i can put inline to disconnect the line-in to the speakers. now the timing circuits.

 

[stuee]

and ive ordered 2 of these. now to wait a month for delivery before i can put it together :/
**broken link removed**

 

[KeepItSimpleStupid]

Stuee:

Initially, I was thinking of longer time delays than 5 and 30, so I just picked a few things:

A timer operating in mode #2 **broken link removed** followed by a one shot. e.g. **broken link removed** These are probably "poor choices"

Hear me out for a moment: Don;t worry about possibe inversion for now.

Just to make it easier to understand, suppose we have an average audio level as a voltage.
We would then create a setpoint with hysteresis for the level we want to trigger at.
Nearly the same as the bar graph display, but not exactly.

You have a free-running oscillator that is "gated" by the set point.
So, below the threshold, the oscillator gets through.
Above the threshold, the oscillator stops.

This is then the trigger signal for a "re-trigerable monostable" with your 5 second time.
So, if it keeps getting triggered it stays, say OFF.

One it is triggered, you need to feed that into a "non-retrigerable timer. A timer that doesn;t reset on a new trigger.
Now this timer changes state instantly and keeps the audio off for 30 seconds.

It's VERY possible that with Liner's TimerBlox chips http://www.linear.com/product/LTC6993-1 (not necessarily just this chip), you can basically achieve your goals.
www.jaycar.com is an .au outfit. You choice might be Farnell or RS electronics.

==

The point is, think about how it could work. A gated oscillator (square wave) + a retrigerable timer followed by an edge triggered non-retrigerable timer.

 

[koolguy]

Hello,
guys what you are trying i don't know.
what is aim of project is noise level??
something simalar

 

[KeepItSimpleStupid]

Well, for one, it looks in the .uk noise levels are a bit stricter than in .au. But, towns have various loudness levels and times. So the landlord gets complaints and .... and finally money making venue goes bust. The city doesn't give you many chances, so you have to hire someone and there goes your profit.

So, you just want something that tells the performers how loud they are with some sort of cut-off level and you don't want one cymbal crash to irritate the band.

So, you measure, preferably with a microphone. Calibrated if your in to those things. Weighted if your in to those things, so it behaves like the human ear.
If you had issues, then you might want to datalog the loundness for the evening.

So, you measure the average loudness, and start counting when it's higher tan it's supposed to be. AHH, it's been greater than the allowed for 5 seconds. Thats a No no. Let''s turn the music off for 30 seconds when that happens. and start over.

Fancy version says more than 5 in a night, power won't come back on.

The "hackers" show up at the next venue and try to bypass the system. At this point it calls the alarm monitoring service wo verifies there's an issue and sends some big bouncer to clear everyone out and lock the doors. The cops are called in and the arrest the hackers. they were the band members and therefore no more shows.
==
Really: Try to keep the sound level within acceptable limits. Turning off the sound when it gets too high is supposed to be a deterrent. It must be done in a way that makes tampering hard. e.g. Nail MDF over microphone. Cut this wire and it's defeated.

So, it's done well when it's part of the building's infrastructure.. e.g box built into the wall with tamper switches and battery backup (maybe).
Conduit back to the main breaker panel.
All outlets in the room go to a locked room where all of the music power can be cut.

As i said. Design for the worst and pick what you need. Add as needed.