The Siren Board

I can't seem to find the decibals statistics for a model 5. How far is the coverage?

Here is a link to a manual with Model 5 info in it: http://www.jeffclifton.com/eric/2-5-SD1 ... 5A154F.pdf

Model 5: 113dB @ 100 ft.
Model 5T: 108dB @ 100 ft.

As far as the range of the siren itself...I have no idea. I have a Model 5 about...well...I dunno how far it is exactly. I figure about 1/4-1/2 mile from me and I can hear it quite nicely. It's especially loud on those cold, still winter nights.

I'm sure someone with more knowledge can help you out further.

It's darn near impossible to put an exact figure on siren range. While it seems to follow that a louder a siren is rated at 100ft (which I believe is determined by tests done in specialized sound chambers, at least at ASC), the further it will be heard, there are a lot of other factors at play. Pitch for instance: a lower frequency will travel farther and penetrates more easily while higher pitch can be heard better over white noise, traffic, etc. From what I've gathered, single tones seem to travel farther as well.

Even if you do have a figure for range, it's useless to rely on since weather conditions make such a huge difference. As Trey mentioned, sirens are definitely heard better at night since sound carries much further and is heard better at night. This is because sound waves bend toward colder air and since it's colder near the ground at night, sound bends toward you. Compare that to a siren heard during a warm summer day, when severe weather is most likely to occur mind you, the sound is bending up and away from you toward colder air above. This is what's known as temperature inversion. Sound also travels more slowly in heavier, more moist air, which is of course the fuel for severe weather.

Hope this helps!