The Siren Board

OK I've got a question about the Eclipse. It's rated at 115 decibles at 100', at 3/4 of a mile away what would the decible output be?I know you could probably here it, I just wanted to know if anyone's got a guestimation on it.

Thanks,

Hmm, somewhere between 50 and 70dB? Only a wild guess though.

Somewhere on the internet is a formula for calculating the sound pressure deterioration over a distance.

Isn't it roughly "double the distance, subtract eight decibals"?

I think you may be right in the basic sense.

Sound In Intensity Level (Sound Pressure Levels)
The unit used for the measurement of sound intensity level is called decibel, dBA sometimes dB for a change in decibel levels. A sound which doubles in perceived loudness, means that there is a change of about10 decibel. This implies that a sound with an intensity change of 20 dB has increased its loudness by a multiple of four. Similarly, a drop of 10 dB in intensity of the sound means that the loudness has dropped to half its original level. If a sound source 100 feet away has an intensity of 90 dB and you were to move to a distance 200 feet from the source, the intensity of the sound would drop by 6 dB (if the distance from the source is doubled, there is a drop of 6 dB). This is true for the behavior of sound outdoors.

Source Level (in dBA)

Faintest audible sound 0

Whisper 20

Quiet residence 30

Soft stereo in residence 40

Cafeteria 80

Cafeteria kitchen 90

Loud crowd noise 100

Accelerating motorcycle 110

Hard rock band 120

Jet engine (75 feet away) 140

Here's a calculator for more accurate figures.
http://www.sengpielaudio.com/calculator-distance.htm
and the page it was from:
http://www.sengpielaudio.com/Calculations03.htm

I've seen the specifications of these sirens on Federal's website.

One with horns is rated 115 DB at 100'.

The city of Smyrna, GA, where I lived for a long time, began installing a siren system about 30 years ago. The original installation began with STH-10s(11 of the 16 are STH-10s).
This siren is rated 115 db at 100'. However..if conditions were right, the sound would often carry well beyond the estimated 1/2 mile radius. I could hear one clearly inside my house with the windows closed.

I haven't noticed the STH-10 on Federal's site(after the Tbolt it's my favorite siren). Is the Eclipse replacing the STH-10?
I know the STH-10 wasn't equipped for battery backup..but it was one fine siren. The Smyrna ones are still in regular use. Every few years the city gives them a fresh coat of yellow paint.

I did noticed that the Eclipse pitch is 525 cycles per second instead of the 675 of the STH-10.

Melvin Potts wrote:I've seen the specifications of these sirens on Federal's website.

One with horns is rated 115 DB at 100'.

The city of Smyrna, GA, where I lived for a long time, began installing a siren system about 30 years ago. The original installation began with STH-10s(11 of the 16 are STH-10s).
This siren is rated 115 db at 100'. However..if conditions were right, the sound would often carry well beyond the estimated 1/2 mile radius. I could hear one clearly inside my house with the windows closed.

I haven't noticed the STH-10 on Federal's site(after the Tbolt it's my favorite siren). Is the Eclipse replacing the STH-10?
I know the STH-10 wasn't equipped for battery backup..but it was one fine siren. The Smyrna ones are still in regular use. Every few years the city gives them a fresh coat of yellow paint.

I did noticed that the Eclipse pitch is 525 cycles per second instead of the 675 of the STH-10.

I love the STH10 too.

As to your question, yes, it is being replaced by the Eclipse.

The STH10 is still on the FWS website:
http://www.federalwarningsystems.com/pr ... ?prodid=27

Here is the story of the Eclipse:

University Park, Illinois-August 2005-Continuing a strong history as the leader in innovative siren design, Federal Signal is proud to announce the release of the Eclipse Siren Series. The series includes the Eclipse8 and the EclipseNH mid-range omni-directional sirens. These sirens are designed to offer warning in hazardous conditions for small to mid-sized communities, but can also be used in large systems to more effectively provide coverage as part of a large community system.


The Eclipse Siren Series utilizes the same motor that has provided the 2001 siren with over 15 years of proven reliability. Additionally, like the 2001SRNB, the Eclipse Siren Series offers the option of DC power operation, but in a mid-range siren. The Eclipse sirens can operate strictly on AC-power or batteries (DC), or AC with battery back-up.


The Eclipse8 and EclipseNH have a maximum sound pressure output of 115dBC and 107dBC, respectively. The Eclipse offers a unique low frequency output with significant power at the first harmonic, resulting in a distinctive dual-tone feature. ?The unique dual-tone feature of the Eclipse siren provides low-frequency coverage while creating high frequency harmonics in the optimal range where most people hear better,? states John Von Thaden, Sales and Marketing Manager.


Additionally, both Eclipse sirens utilize a 100% aluminum design and can be roof or pole mounted. The EclipseNH and Eclipse8 sirens are maintenance-free, and are backed by an industry leading 5-year warranty. The Eclipse Siren Series is an ideal replacement for existing 2T22, Model 5, and STH10 sirens.


?The Eclipse Siren Series continues Federal Signal?s goal to offer our customers highly reliable products that meet their growing needs and insure they are always prepared,? added Von Thaden.


Federal Warning Systems, a division of Federal Signal Corporation, is the worldwide leading provider of outdoor warning and remote notification devices for the public safety industry.


Federal Signal Corporation is a global manufacturer of leading niche products in four operating groups: environmental vehicles and related products, fire rescue vehicles, safety and signaling products, and consumable industrial tooling. Based in Oak Brook, Illinois, the company's shares are traded on the New York Stock Exchange under the symbol FSS.

If anything the STL-10 is a good siren. Topeka has 3...and i have heard one in person...and have a recording...it sounded awesome...and from what i hear you can hear it miles away...altho i live a mile and a half from it i have 2 2001s, a model 5, a thunderbolt, and many other sirens drowning it out.

Thunderbolt wrote:

The Eclipse8 and EclipseNH have a maximum sound pressure output of 115dBC and 107dBC, respectively. The Eclipse offers a unique low frequency output with significant power at the first harmonic, resulting in a distinctive dual-tone feature. ?The unique dual-tone feature of the Eclipse

The recording I heard was not of a dual-tone siren. The Eclipse sounds pretty much like a slower-moving Screamer. Also, how can they claim to have a low tone, when the Eclipse sounds just a step below a Model 2 in pitch? The only truly low-pitched siren Federal ever made was the STL-10.

Daniel wrote:

Thunderbolt wrote:

The Eclipse8 and EclipseNH have a maximum sound pressure output of 115dBC and 107dBC, respectively. The Eclipse offers a unique low frequency output with significant power at the first harmonic, resulting in a distinctive dual-tone feature. ?The unique dual-tone feature of the Eclipse

The recording I heard was not of a dual-tone siren. The Eclipse sounds pretty much like a slower-moving Screamer. Also, how can they claim to have a low tone, when the Eclipse sounds just a step below a Model 2 in pitch? The only truly low-pitched siren Federal ever made was the STL-10.

No idea...

Again, Federal, not me!

If they think that the Eclipse is dual tone, they must not have known what they were doing when it came to the XT22, SD10, ect..

Could they be refering to the resultant tone created by a dual-tone
siren?

What does Federal mean by 1st harmonic?

Has anyone compiled a list of all the sirens and their frequencies?
I get totally lost.

Thank you,