Have you seen this?

[SirenMadness]

Actually, you do gain a slight boost in sound from that tower of sirens, due to the spacing of the sirens; you get a wider distance between the starting-points for the sound.

[Robert Gift]

Actually, you do gain a slight boost in sound from that tower of sirens, due to the spacing of the sirens; you get a wider distance between the starting-points for the sound.

But if they match frequencies, cancellation may diminish sound level and therefore distance.
It is a costly mistake.
Far better to get one more powerful siren than two less powerful units.
However, better to have two sirens covering their respective smaller areas than one bigger siren.

[SirenMadness]

You may not always get cancellation.

[Robert Gift]

You may not always get cancellation.

Cancellation occurs when you have two identical frequencies from two different sources. For example, a siren speaker in the lightbar and another on the grill.
Best to have both in one place or the other.

[SirenMadness]

Yeah, but not all of the waves from the sirens necessarily interact.

[Robert Gift]

Yeah, but not all of the waves from the sirens necessarily interact.

They all interact. It doesn't matter what the source. It is a matter of where the cancellation nodes occur.
If they are very slightly different frequencies, they will not cancel.
Would be interesting to hear if both sirens happen to synchronize and emit identical frequencies.

[SirenMadness]

Maybe the two sirens do a specific signals when their wail overlap.

[Robert Gift]

I'd love to hear what they do.
I assume they are on one controller so they act together.

[EL1998P71]

In Flint, MI When I drove thru downtown, I saw a Thundebolt a few feet away from a 2100-130, they were both connected and switched on at the time.

[Robert Gift]

That must have been a fascinating sound!
Presumably they will remove the Thunderbolt?

Yesterday my wife got to flip the switch and sound Lassie (2T22) (First time she heard the siren in person.)
She was able to discern Lassie's two notes D5 and F5 - with my whistling them, but she could not discern the Bb2 resultant.