creating an electonic siren sound

Hi,

I'm trying to create an electronic siren sound.  Perferably with something like Z3ta2, or Alchemy etc.  Anyone have any ideas?

Thanks,

Sirens are typically dual-tone, so you'll want two square wave oscillators that can be tuned independently. Z3ta+ should be able to do it, since it features multiple independent oscillators. Use pulse waves, which are similar to the waveform of an old-time air-raid siren, which works by spinning a perforated wheel in front of a blower. I'd also use a short delay to simulate the sound bouncing off nearby buildings.

and if you're looking for too much detail, the British ambulance goes from a root note down a 4th.  I don't know if their other emergency vehicles have the same spacing, but I like those sirens.

If it was me, i'd try to program a mod wheel to jump that spread and play by hand for the tempo you want.