Nashville, Tn decides to change tone length of their Sirens

[Alasiren1977]

After much nasty emails to the EMA director about their crap ATI system, they decided to change how long they blast the sirens during Tornado warnings.

http://www.wsmv.com/video/15300292/index.html

[jkvernon]

They really need to change the tone itself along with the lenth.

[Whelen Rules]

They really need to change the tone itself along with the lenth.

You are correct. I would suggest Nashville start using the wail tone. The city of Tullahoma repeats sounding the sirens every 3 or 4 minutes until the tornado threat for that particular storm is over.

[Alasiren1977]

Ya apparently a lot of people are complaining that they can not hear the sirens. I guess their quick fix for having the worst siren in production is to make it go off longer, which is not a bad idea for any town with sirens but now it is going to be a longer dial tone noise instead of three minutes. I sent them so many emails about the type of siren being just plain "rotted" that they decided to try to shut me up by doing this.

[kswx29]

Their nasty E-mails made the situation worse...they will keep re-sounding them every 8 mins!

[Alasiren1977]

Their nasty E-mails made the situation worse...they will keep re-sounding them every 8 mins!

How is re-sounding them every 8 minutes worse?! Every siren system should do that! Everybody's email including mine was not about making them sound the sirens longer anyway, it was about adding more sirens to their 5 year old system and getting better ones!

[Whelen Rules]

Well obviously they aren't going to replace the entire system which costed over 1 million dollars (wasted) that is only 5 years old. They could add to the system but I doubt it. Next thing is I would suggest like I said earlier that they switch to the Wail tone which stands out better against ambient noises. Activating them more than once is ideal. Most cities in Tennessee do activate their sirens in intervals during the warning.

At night the sirens sounding more than once, especially in advance to the storm hitting, does help in waking those who are with in half a mile or a little more of the siren unit.

I am an advocate of using the attack or wail tone during warnings due to its more effective attention getting tone. The alert tone blends in to well with ambient noises at a distance from the siren unit.

[holler]

When the Mods and DSAs at the base go off, the only time we can hear them inside is when they windup or winddown.

Does ATI have any different tone chips available, perhaps one that is a little bit lower, about like a single tone mod?

[ronatello]

Considering that the tone of the ATI is about 1KHz, They should include a minor third below that high C which would come closer to the Federal EOWS minor 3rd tone. And make that wail up and down.
I think the reason why ATI went with such a high frequency is because of the (dubious) design of the speaker / horn units. The small horns probably do the best around 1KHz.
<my $.02>
Hey ATI, double the size of that horn, use a bigger and more robust transducer, and drop that tone down to 500Hz! And while you're at it, quit using those $5 radio shack PA horns
</my $.02>

[ver tum]

the reason why ATI went with such a high frequency is because of the (dubious) design of the speaker / horn units. The small horns probably do the best around 1KHz.

I was just thinking almost the exact same thing. Also, I think ATI drivers don't do well with lower tones from what I've heard.

The problem with the ATI's is very obvious. The 1000 HZ tone with no startup or wind-down, just doesn't carry very far. If I was very far away from one of the ATI's, I might not even recognize it as a siren. It has the same tone as some machines produce when they are whining. The EM in Nashville should at least use the voice capability of their ATI's.

Here in Louisville, Kentucky, our Emergency Management now sounds the sirens throughout the duration of a tornado warning. They used to sound them only three times, which was probably enough. I've heard several complaints since the policy was changed. However, during a storm, it is important that the sirens are sounded more than once, because bad weather conditions can prevent the siren receivers from getting the activation signal. This happened here in Louisville back in May of 06 with the Doss Highschool Thunderbolt. Fortunately, the siren had already sounded successfully once, so it wasn't as big of an issue as it could have been.

BTW, the siren sounding in that video is definitely not an ATI!