The Siren Board

I am just going to throw this in here, we do have a wiki, and though it is a bit empty right now, there are some sirens with production sates, so you can go look them up so you don't have to ask about dates and have "I guess" or "I think" answers to that, and a few other bits of info.

Also, even though it has been said already, I'll say it again to keep OT. It has been confirmed from Federal that the 500 is the direct replacement for the Thunderbolt, while not being made right after, it is meant to be its replacement.

mrboojay wrote:I am just going to throw this in here, we do have a wiki, and though it is a bit empty right now, there are some sirens with production sates, so you can go look them up so you don't have to ask about dates and have "I guess" or "I think" answers to that, and a few other bits of info.

Also, even though it has been said already, I'll say it again to keep OT. It has been confirmed from Federal that the 500 is the direct replacement for the Thunderbolt, while not being made right after, it is meant to be its replacement.

508* Dates* Lol no but thanks for pointing the wikki out.

coastalsyrolover wrote:Another question here... The 2001 is rated at 130 but the equinox is rated at 125. Now federal could have either gotten those numbers from the rate formula or actually at 100 feet or both... (They test for it better now adays than they used too...) But my question is: why is the equinox so much quieter than the 130? Why hasn't federal signal used a siren with the fully adjustable frequency since the bolt? Is it just not needed?

I'm assuming cost. It's easier to produce multiple, different products than it is a single, multipurpose one. Hence why PA-capable electronic sirens are so expensive

I'm not so sure. I see a lot more 2001's around than 508's.

CrazyForThunderbolts wrote:I'm not so sure. I see a lot more 2001's around than 508's.

That's because the 2001 has been out since the late 80s early 90s. The 508 didn't come out until 2012-2013 I think.

SoundMaster 391 wrote:

Brendan Ahern wrote:Somewhat off topic, but when did the modulator come out?

This is just a total guess. But I think they came out around the mid to late 90's. I was looking at a old news article about the new Mod sirens that Honolulu was starting to put up. The date of the article was 1999 so I have to guess that they were maybe being made for a few years before that.

1995. This has been researched extensively, so stop guessing and use the wiki! https://airraidsirens.com/wiki/index.ph ... ren_Series

As for the lower output of the Equinox, as mentioned it was thrown together. The projector and horns are not tuned for the lower frequency. Again, the wiki. https://airraidsirens.com/wiki/index.php?title=Equinox

Now, the reason that sirens don't have variable pitch like the Thunderbolt did: The pitch change on the Thunderbolt is done by changing the RPM of the rotor. On a normal siren, this would also change the volume of air, and thus the sound output, as the rotor acts as a centrifugal blower. The Thunderbolt and Hurricane both have a blower that feeds air into the siren head, maintaining the same volume of air regardless of rotor RPM. The Hoermann HLS series use compressed air to feed the chopper.

Ziginox wrote:

SoundMaster 391 wrote:

Brendan Ahern wrote:Somewhat off topic, but when did the modulator come out?

This is just a total guess. But I think they came out around the mid to late 90's. I was looking at a old news article about the new Mod sirens that Honolulu was starting to put up. The date of the article was 1999 so I have to guess that they were maybe being made for a few years before that.

1995. This has been researched extensively, so stop guessing and use the wiki! https://airraidsirens.com/wiki/index.ph ... ren_Series

As for the lower output of the Equinox, as mentioned it was thrown together. The projector and horns are not tuned for the lower frequency. Again, the wiki. https://airraidsirens.com/wiki/index.php?title=Equinox

Now, the reason that sirens don't have variable pitch like the Thunderbolt did: The pitch change on the Thunderbolt is done by changing the RPM of the rotor. On a normal siren, this would also change the volume of air, and thus the sound output, as the rotor acts as a centrifugal blower. The Thunderbolt and Hurricane both have a blower that feeds air into the siren head, maintaining the same volume of air regardless of rotor RPM. The Hoermann HLS series use compressed air to feed the chopper.

Sorry about that.

coastalsyrolover wrote:Another question here... The 2001 is rated at 130 but the equinox is rated at 125. Now federal could have either gotten those numbers from the rate formula or actually at 100 feet or both... (They test for it better now adays than they used too...) But my question is: why is the equinox so much quieter than the 130? Why hasn't federal signal used a siren with the fully adjustable frequency since the bolt? Is it just not needed?

Don't quote me on this one, but I believe it is because the 2001 was specifically designed for high-frequency sound output. It might have something to do with the way the air intake or the projector are designed. If they had more time, they would've probably made some slight modifications to increase the sound output. But, seeing as this was a rushed job to prevent Federal from loosing another nuclear plant contract to ASC, half the output didn't really matter.

BTW, was the Equinox originally made for the Perry plant or the Beaver Valley plant?

Manitoba wrote:Don't quote me on this one, but I believe it is because the 2001 was specifically designed for high-frequency sound output. It might have something to do with the way the air intake or the projector are designed. If they had more time, they would've probably made some slight modifications to increase the sound output. But, seeing as this was a rushed job to prevent Federal from loosing another nuclear plant contract to ASC, half the output didn't really matter.

Ziginox wrote:As for the lower output of the Equinox, as mentioned it was thrown together. The projector and horns are not tuned for the lower frequency. Again, the wiki. https://airraidsirens.com/wiki/index.php?title=Equinox

To answer the other question, I don't think anyone knows who had them produced first. I think Beaver Valley's are older than the ones at the Perry Plant and were the first to caught in the wild, but it's unknown if they were the first. The earliest video of one online is from 2011, one of Beaver Valley's Equinoxes located in Chester, West Virginia. According to the uploader it was actually louder that the Allertor it replaced.
https://www.youtube.com/watch?v=7LIXvkNbZnA

It might only seem louder because of A weight... But who knows?