Bumping this too, finally got more information about the KM-Europ siren core that my town has. It’s a 1kW unit, or rather we suspect it is. It was tested this year, yep, a surprise test, and blimey, that thing is B R U T A L.
From what I could find on KM-Europ’s website before it went defunct, this model was advertised as to be able to kick out 120dB, just shy ahead of an ACA Allertor!
Here is a picture of it, yep it is pretty large, and it’s both weird and creepy-looking at the same time. The cage underneath its base is the air intake.