What would happen to dB ratings if we tested them outside?

[acoustics101]

The actual method of testing isn't as important as including the attenuation due to atmospheric absorption loss. This loss is about 1 dB/1000 feet for a pure tone at 500 Hz and is proportional to the frequency. This, of course, is in addition to the inverse square law loss of 6 dB/doubling the distance. This would give us something real to work with. Of course there are other variables that can't be controlled, but this would at least give us a way to quantitatively compare the performance of one unit against that of another. As things currently stand, comparison is only on a qualitative basis.

We need to stop using the estimated loss of 10 dB/doubling the distance. The laws of physics and acoustics simply don't support it. According to this method, frequency doesn't even enter into the equation, when in fact it is one of the most important variables.

[Urban Disturber]

Regarding the acoustics of traditional motor sirens...

Whilst playing with my little Carter Minimite 24V siren, I noticed that wind strength and direction play a BIG part in the loudness of the siren.

At certain speeds, the wind reacted with the siren and almost cut the sound out completely at times- only for extremely short periods, creating a random volume effect.

You have to remember that the siren is a mechanical device which works purely using basic physics!

the loudness of the sound depends on how much air is chopped through the holes at that particular moment in time, therefore, outdoor testing can potentially give really inaccurate sound level results if the air current is allowed to alter the air entering and exiting the siren.

[SirenMadness]

Outdoor testing is a good method provided that the air is practically still while testing.

[sirenita]

I drove down the road yesterday and saw three 2001s rather close to each other - maybe a mile apart between sirens? I was shocked that they were so close to one another. I was thinking, if a county has money for 3 of these wouldn't it have money for one that could cover the area of those three or is it better to have three??

I had my first in-person test experience today in the county mentioned above. I arrived about a minute late due to a long red light, and so I missed the windup.

here are the highlights:

I didn't hear the siren until I was maybe 200 feet away. I parked almost directly underneath it and found it to be not very loud at all. this explains why I have never heard the siren that is less than a mile from where I work during tests (I've never been here during an actual warning; I make it a point to gtfo)

it rotated VERY slowly. maybe 1 RPM. and it returned to its original position. I know its original position because I pass it every day. it did however, change from its position pre-last week's storms. all of the sirens I pass every day are 180 degrees from their previous position.

I think they need to get the dude from american restoration to work on these sirens so they can be heard from 10 miles away

[uncommonsense]

I drove down the road yesterday and saw three 2001s rather close to each other - maybe a mile apart between sirens? I was shocked that they were so close to one another. I was thinking, if a county has money for 3 of these wouldn't it have money for one that could cover the area of those three or is it better to have three??

I had my first in-person test experience today in the county mentioned above. I arrived about a minute late due to a long red light, and so I missed the windup.

here are the highlights:

I didn't hear the siren until I was maybe 200 feet away. I parked almost directly underneath it and found it to be not very loud at all. this explains why I have never heard the siren that is less than a mile from where I work during tests (I've never been here during an actual warning; I make it a point to gtfo)

it rotated VERY slowly. maybe 1 RPM. and it returned to its original position. I know its original position because I pass it every day. it did however, change from its position pre-last week's storms. all of the sirens I pass every day are 180 degrees from their previous position.

I think they need to get the dude from american restoration to work on these sirens so they can be heard from 10 miles away

If its only rotating 1 RPM, its broken, period. I betchya its a DC only siren and the batteries are dying. Might want to report it.

[TboltTX1]

I think they need to get the dude from american restoration to work on these sirens so they can be heard from 10 miles away

Along with waking the dead?

[SIRENMAN]

BOTTOM LINE ANSI TESTING S12.14 is testing for outdoor sirens in a fixed location. S12.14 gives specific conditions on trees bushes and clear area in a still wind conditions. PERIOD END OF QUOTE.

[Crazywarriorman]

BOTTOM LINE ANSI TESTING S12.14 is testing for outdoor sirens in a fixed location. S12.14 gives specific conditions on trees bushes and clear area in a still wind conditions. PERIOD END OF QUOTE.

So what if Federal didn't show the sound ratings, cities keep buying their sirens, and probably will for a long time. There's no soild proof any siren company's done ANSI testing unless you post up the results, or you actually see them test it. Until then we can't say anyone has done this "ANSI" testing right, or even done it at all. I mean this really isn't that big of a deal in my opinion, I'm sure alot of more people would have been killed if they didn't hear the sirens during last months outbreaks. I mean when you look at it that way, that says that they work, with or without the testing.