Sound Level cut off.

[stuee]

I did try asking for help to make this a bit ago but no one helped but just told me how to run my life blah blah.
Without people asking about my life and situation and telling me what i should do i would appreciate some help with making this.

What i was thinking is like the pic i drew shows.

I would like a microphone with adjustable sensitivity which then goes to an ic level meter, on the 1st red led it triggers a 12v (police siren light) to activate.
When the last red led is on a timer starts (again adjustable from say 10 secs to 1min) then after that time happens it then jumps to another timer which i can adjust from 1m to 5 mins. When it triggers the second timer that outputs to 2 car 12v relays which are in always on mode inline on the speaker + wires and triggers the relay to disable them both till the time ends or they turn down the audio so the timers are no longer powered because the leds are not lit up.

I hope this makes sense and someone can assist me to make this.

Cheers
Stuart

 

[alec_t]

When it triggers the second timer that outputs to 2 car 12v relays which are in always on mode inline on the speaker + wires and triggers the relay to disable them both till the time ends or they turn down the audio

I hope this makes sense

Sorry, it doesn't. Can you explain how they can be disabled and always on? How do relays 'turn down the audio'? Why do you need two timers? Are you trying simply to make a sound-triggered siren which stays on for a pre-set time (if so, there are probably easier ways of doing it)?

 

[audioguru]

Your simple block diagram is missing all the complicated details:
1) A microphone needs a preamp circuit.
2) The level detector needs an LM3915 IC circuit.
3) The police light needs a driver circuit and maybe a timer so it does not simply blink.

What is a siren light? A siren makes sound, not light.
I do not know why you want to use relays to disconnect the speakers instead of simply muting the amplifier instead.

 

[ClydeCrashKop]

Maybe this will help you get started.
**broken link removed**

 

[4pyros]

Your IC should be a LM3915, and you are going to need a mic pre amp.
The big problem is you can not switch speakers off like that with out blowing up your amps.
You need to "mute" the input to the power amp.

 

[Nigel Goodwin]

Your IC should be a LM3915, and you are going to need a mic pre amp.
The big problem is you can not switch speakers off like that with out blowing up your amps.
You need to "mute" the input to the power amp.

Not at all, while it's certainly preferable to mute the input to the amp it won't damage the amp disconnecting the speakers (in fact quite the opposite), UNLESS it's a valve amp (which is unlikely).

 

[stuee]

Thanks for your replies. ill try answering all questions the the best of my knowledge

When i mean always on i mean the speakers are wired through the relay on pin 30 / 87a then when 12v is applied to pin 86 the switch / relay will disable the audio throughput.

The reason im making this is to have this set at a certain volume at the other end of the room for reasons, then have it set so when the sound gets too loud above my set level it will give a warning (rotating light light on a old school police car) if the light stays on for a certain amount of time because the sound isn't turned down(again i choose time) then it jumps to another timer that triggers the relays on pin 86 that disables the sound for the time i choose.

I hope that made more sense.

I know i was missing circuits but i put the drawing together as a description to make it easier to work out to my explanation.

 

[4pyros]

Not at all, while it's certainly preferable to mute the input to the amp it won't damage the amp disconnecting the speakers (in fact quite the opposite), UNLESS it's a valve amp (which is unlikely).

I am pretty sure this is not the preferred way to do it.

 

[Nigel Goodwin]

I am pretty sure this is not the preferred way to do it.

Which is exactly what I said - I was simply correcting your incorrect assertion that disconnecting the speakers would damage the amp in any way.

I seem to recall that the commercial units for doing this often simply turn the mains off?.

 

[4pyros]

Which is exactly what I said - I was simply correcting your incorrect assertion that disconnecting the speakers would damage the amp in any way.

I seem to recall that the commercial units for doing this often simply turn the mains off?.

ok so I dumbed it down for the OP. I probably will do more damage to the speakers than the amp, ether case don't do it.

 

[audioguru]

You forgot to say what is the sound from the speakers. Music? Speech?
Their sound levels are peaks of sound with much lower levels or silence in between. The average level is much lower than the peak level. Then your police light will simply blink and might not be turned on long enough for each blink to make any light.

The circuit that disconnects the speakers or mutes the amplifier will also work only for the peaks so the sound will quickly jump on and off intermittently unless you have some kind of very slow averaging circuit drive it.

 

[stuee]

the sound will be music 99% of the time. i would like to tune the mic to pickup and be 1st green when its getting close to be too loud, so in reality the lights shouldn't come on at all if its not turned up over the limit.

 

[audioguru]

Didn't you hear me talk about peak sound level and average sound level? The peak level can be 10 times more than the average level. Peaks occur only for short durations (except acid rock blasts all the time).
Some music has "the beat" the loudest. Do you want the police light to blink with the beat of the music?

If you are making this circuit to detect when the sound level is loud enough to cause hearing damage then you need to detect the average level, not the momentary peak level, but of course extremely loud momentary peak sounds (thunder from nearby lightning) can also cause hearing damage or if you have a loud speaker very close to your ears.

 

[Nigel Goodwin]

ok so I dumbed it down for the OP. I probably will do more damage to the speakers than the amp, ether case don't do it.

It wouldn't damage the speakers in any way either, how could it?.

 

[stuee]

i understand about the peak and average, thats why i want the timer circuits so when the sound does his into the red the police light comes on as a warning, if they dont turn down the music a little then it will activate the other timer which will turn off the music.
The light is the same as this https://www.google.com.au/search?q=...ng-Police-Beacon%2FM%2FB0032EVL1S.htm;250;250 and it is 12v.

 

[audioguru]

When the sound level is high enough for a moment to light a red LED on the LM3915 then the 1st 555 is triggered and its output turns on the driver for the police light (we do not know how much current it uses).

If they turn down the volume then nothing turns off the 1st timer. Maybe a peak detector should be used instead of the 1st timer. It will turn off if it is not triggered anymore.

What will activate the mute circuit? What will give an output after the sound level is too high for a certain amount of time? A 555 timer will not work because its output is the same before it is triggered as when it has timed out.

 

[stuee]

my mate owns a car wreckers so i can get as many 12v/30a relays as i want (im not sure of the 12v input current to trigger the coil) The light i want is just on as soon as the 1st led comes on without a timer. The timer will be triggered though to start the mute sound timer, 1st Red Led >light on > starts timer > if music not turned down then the timer reaches its point and activates the 2nd timer which controls how long the sound is disabled for. This is was going to use again a car relay on each channel L/R then i can use the 12v to activate the relays and disable the audio. Sorry if im not making sense but appreciate you assisting me.

 

[alec_t]

So, something like this?

 

[audioguru]

A 555 timer is made to turn on something for a timed duration when it is triggered. When it times out then it turns off like before it was triggered.
You need a timer or something that does nothing while it is timing but its timing can be stopped when something detects that the sound has been turned down. If the sound is still too loud then the timer times out and turns off the amplifier. But this timer also turns off the amplifier before it begins timing so it WILL NOT WORK. Maybe a microcontroller can be programmed to do what you want.

Stuee, G'day! I guess you are DOWN UNDER because your male friend is your mate. My female wife is my mate.