Model L wrote: ↑Thu Mar 14, 2019 2:36 pm
to an extent, yes.
more air would be able to escape at once, so the blower would not be able to build as much pressure, sacrificing the high decibel level of thunderbolts
The 1000 has only 5 wide openings and can reach up to 130dB. I think the factor here is the width of the chopper holes.
If you see closely on American Dual Tones (aka Single chopper & stator sirens) especially those with a single tone variant in the line, the chopper & stator openings on the dualtones are narrower than singletone counterparts.
However when it comes to British designs which implemented a dual rotor design, the sound output isn't that lod due to the lacking of directional horns. Most directional sirens are louder that their omnis since the sound beam is focused at one spot, hence the phrase unidirectional.