The Siren Board

This is being posted 17 minutes after I heard a 2001-SRN growl off in the county. I was just asleep like usual and then at 5 today, the 2001 just growls. If anyone knows what happened, please let me know.
*update: The Mccord Junior high school SRN just went off at 5:25 am EST

Why would a siren system do a growl test so early in the morning? Does not make any sense to me. I mean I know some sirens are used as time signals (E.G. Noon blasts, 6 PM, curfew) but a growl test even before the ssun is up? *Scratches head*

Definitely sounds like a malfunction situation.

siren fan wrote: ↑

Thu Jan 19, 2023 10:04 pm

Definitely sounds like a malfunction situation.

That is what I thought

Sounds more like a silent test, I've heard of places doing it in the early morning hours like that before. I guess it wasn't silent enough this time lol

sirensandfirealarms wrote: ↑

Sat Jan 21, 2023 2:19 am

Sounds more like a silent test, I've heard of places doing it in the early morning hours like that before. I guess it wasn't silent enough this time lol

IIRC yes, the "silent test" for both Federal signal and ASC is a growl that the controller uses to check if the motor is drawing current.
https://www.youtube.com/watch?v=eztxVBku1pk here is a video of one of these "silent tests". not sure if I'd call it silent
https://www.youtube.com/watch?v=Z52fAmNs8nw and another for good measure.

Model L wrote: ↑

Sat Jan 21, 2023 2:44 am

sirensandfirealarms wrote: ↑

Sat Jan 21, 2023 2:19 am

Sounds more like a silent test, I've heard of places doing it in the early morning hours like that before. I guess it wasn't silent enough this time lol

IIRC yes, the "silent test" for both Federal signal and ASC is a growl that the controller uses to check if the motor is drawing current.
https://www.youtube.com/watch?v=eztxVBku1pk here is a video of one of these "silent tests". not sure if I'd call it silent
https://www.youtube.com/watch?v=Z52fAmNs8nw and another for good measure.

Those definitely weren't 'silent tests'. To me, they were 'partially silent' until the siren head stopped moving and then the 'growl'. Really strange to me. I know that Whelen's outdoor systems can do silent testing, and unlike most sirens, there is absolutely no sound at all unless the person who's doing the testing wants to see if the speakers are working.

In my honest opinion, this doesn't sound like a silent test at all. Why they would have done this at five in the morning? It probably was an accidental activation. I don't see why the EMA would test so early in the morning. Knowing how much citizens just love to complain about things like this, it's just plainly stupid to activate at that hour. People hate being woke up by a loud tornado siren.

Still, it doesn't put activating early in the morning as a test out of the question.

siren_face2000 wrote: ↑

Sat Jan 21, 2023 3:08 am

Model L wrote: ↑

Sat Jan 21, 2023 2:44 am

sirensandfirealarms wrote: ↑

Sat Jan 21, 2023 2:19 am

Sounds more like a silent test, I've heard of places doing it in the early morning hours like that before. I guess it wasn't silent enough this time lol

IIRC yes, the "silent test" for both Federal signal and ASC is a growl that the controller uses to check if the motor is drawing current.
https://www.youtube.com/watch?v=eztxVBku1pk here is a video of one of these "silent tests". not sure if I'd call it silent
https://www.youtube.com/watch?v=Z52fAmNs8nw and another for good measure.

Those definitely weren't 'silent tests'. To me, they were 'partially silent' until the siren head stopped moving and then the 'growl'. Really strange to me. I know that Whelen's outdoor systems can do silent testing, and unlike most sirens, there is absolutely no sound at all unless the person who's doing the testing wants to see if the speakers are working.

Whelen's and other fully electronic sirens are able to silently test by passing an inaudible tone in the range of 16-20khz through the drivers at a very low volume and checking for current draw on the amplifier side. Mechanical sirens of course are inable to due this, as any motion in the chopper will cause at least some audible noise. My whelen's silent test is about 17khz and I think it has drifted down over time as whelen's manual notes it should be 20Khz. it is barely audible as a slight hissing/whining noise when SI-Test is occuring.