north dakota siren hunt.

[MattDean1003]

That's just a standard air intake for the M series. There is one of these on the top corner of a bank in Jefferson, GA. It sits inside of the 90 degree angle on the roof of the building. I've always wondered why the intakes are in the shape of a horn when the sound comes out of the shrouds over the rotors.

-Matt Dean-

[Robert Gift]

The horns may serve to guide the air into the rotors more smoothly
with less turbulance. This may increase efficiency.

Also, I was surprised to discover that much sound comes out of the rotor intake! -at least from my siren flashlight siren.

So, maybe they are making more effficient coupling of sound to the atmosphere using a horn.

I think the stator "hoods" are counterproductive.