3T22 horn removal - does it really matter?

[Daniel]

I was in Mount Angel, Oregon, last month and noticed that they had removed more horns from their 3T22. I suppose it is because a senior apartment complex was just finished across the street and the siren is eye level with the third floor windows. I heard this siren four miles away one night (facing the other side of the siren with the horns as in the "before" picture), and the high note was a little louder, but I heard both tones. From the apartments across the street facing this side of the siren, will the removal of more horns really make a noticeable difference? Would it be better, at least aesthetically, to remove them all?

BEFORE:


AFTER:

[hobbeekid]

Maybe they started taking them all off and just have'nt finished the job yet...

[Jim_Ferer]

You'd think it would make a significant difference over distance but not much difference from across the street.

[texaschad25]

That thing looks like it has been in a fight . . .

[Robert Gift]

Poor 3t22
Now a 3t9.
To stop sound emitting from the cones facing the building, I'd simply replace the mesh screens, held in place against their stator ports by the cones, with sheet-metal rectangles.

Or would that cause a rotor air pressure balance problem?

Here, Lassie has only 3 of her lower and 4 of her upper projectors attached.
They cover a 90-degree arc facing the trailer park.
She is in the southwest corner of the park.
When I have time, I'll attach all of her cones.
It's a little tricky because she is right against the waste water treatment plant sewage digester.
(If I fall in, no one on my fire department is willing to perform a rescue!!)

[Cyrun]

Federal Signal told me we would "void" our warranty on the STH10 we recently installed if we restricted the airflow output in any way. I know the warranty for the 3T22 is long past, but I'm sure FS would not recommend it.

[Robert Gift]

Federal Signal told me we would "void" our warranty on the STH10 we recently installed if we restricted the airflow output in any way. I know the warranty for the 3T22 is long past, but I'm sure FS would not recommend it.

Thanks for that information.
Did they indicate why?
Or is the warranty voided if any change or alteration is made?

[Cyrun]

The Tech I spoke to said the siren is designed to operate a certain way and any alterations to the elecrical requirements, air intake or discharge output would void siren warranty. He suggested either mounting a baffle(not attached to unit) to limit sound in a certain direction, or install a lower decibel unit (model 2).
I would think by not having the projection horns attached on that 2/3T22, it exposes the unit further to inclement weather.

[Robert Gift]

The Tech I spoke to said the siren is designed to operate a certain way and any alterations to the elecrical requirements, air intake or discharge output would void siren warranty. He suggested either mounting a baffle(not attached to unit) to limit sound in a certain direction, or install a lower decibel unit (model 2).
I would think by not having the projection horns attached on that 2/3T22, it exposes the unit further to inclement weather.

Thanks, Cyrun.

I assumed an unattached baffle would be the only proper alternative.
But that can be expensive and unsightly, especially difficult when pole-mounted.

(This will be Lassie's first operation in winter since the early 1990s.
But now she in mosty naked - only 7 cones attached.
Before she does her first Saturday of the month howl, I physically turn and inspect her rotor.
After each test, I position her rotor so that both upper and lower ports are closed by the rotor fins.)

[Daniel]

In Dallas, Oregon, the city wrapped a long strip of something like canvas across the mouths of the horns of their STH-10 that reduced the sound output somewhat. This was in response to (surprise!) a complainer who wanted the noon whistle silenced after decades of use.