What is the Db rating for the Federal STH-10?

Wed Jan 30, 2008 3:04 am

I am curious as to the decibel rating of the Federal STH-10? My hometown is installing one in a newly annexed area of town and I am wondering if that siren is a good siren.

Wed Jan 30, 2008 4:38 am

I believe it is 115db. at 100 feet. A tested, tried and true siren. The only drawback is that it needs to be mounted high (at least 25 feet).

Wed Jan 30, 2008 1:41 pm

Conversely, the low pitched counterpart, the STL-10, is also 115dB at 100 feet.

Wed Jan 30, 2008 9:37 pm

Why should it be mounted high?

Thu Jan 31, 2008 12:40 am

A tested, tried and true siren

slant-40...a very good description of the STH-10...and so true.

The STH-10 is my 2nd favorite after the Tbolt. I do recall seeing somewhere in Federal literature that its db rating is 115 at 100'.

Smyrna, GA, where I formerly lived, has 11 of these sirens in its system. The original installation began in late 70s; others were added until there were 11(also have 2 Tbolts and 3 Whelens in the system).

I lived about 4 blocks from the STH-10 at the former police station; could easily hear it inside my house with the windows closed(this siren was relocated about a block and half down street after police station moved).

STH-10 has a great startup sound and a LONG winddown. Even though it's a single tone siren, it can't be mistaken for anything else.

Originally Smyrna tested the sirens at noon every Saturday(later changed to once monthly on 1st Wednesday). Although I could only hear the police station siren during the test, I could hear 2 others winding down.

The sirens are still in place, and, to my knowledge, still tested regularly and sounded for tornado warnings. A few years ago they were given coats of fresh yellow paint which made them look sharp!

Thu Jan 31, 2008 3:42 am

Nelso90 wrote:Why should it be mounted high?

Because if you mount it low - the sound waves bounce off surrounding objects resulting in reduced carry. This is not so true with lower-pitched sirens, like STL-10 and some T-Bolts - the lower frequencies tend to be heard better inside for some reason. Bethpage NY is an example. They placed an STH-10 on their Plainedge station at the same height as the previous siren (a Gamewell diaphone) and found that the vols couldn't hear it. They then raised it on a platform set about 20 feet high and that solved the problem. Floral Park Centre NY has a roof-mounted STH-10 that can barely be heard a mile away while the neighboring town of New Hyde Park has the same siren mounted on a 30-foot pole which carries for a distance of 2 miles plus.

Thu Jan 31, 2008 5:54 am

Are the STL-10 and STH-10 the same rotor/stators of a 2t22?
STL-10 is 10 port/projectors and STH-10 is 12 port/projectors?
They sure look the same as I recall.
Thanks

Thu Jan 31, 2008 6:53 am

The 2T22 uses Model 3 rotors, while the STL-10 and STH-10 use rotors larger than that of a Model 5 even.
Top rotor is from Model 5, bottom from STL-10

Thu Jan 31, 2008 12:07 pm

Interesting! Thank you.
I did not know they had "models" of rotors and stators.
Is the top rotor the same used in a 2t22? Appears it is bi-directional.

Thu Jan 31, 2008 12:16 pm

Robert Gift wrote:Interesting! Thank you.
I did not know they had "models" of rotors and stators.
Is the top rotor the same used in a 2t22? Appears it is bi-directional.

"Models," as in a rotor that would go in a Federal Model 3. So yes, the top one goes is used in the Model 5. The bottom, a STL-10. I am pretty sure Adam has already made this quite clear.