Ok so my buddy and i always have little competitions on who knows how to do the coolest thing, i was talking to a few fellow medics and they said they changed their sirens on their truck, not like the pitch or anything but made it a totally different siren. Does anyone know how they would have even gone about it aside from buying new hardware for their truck? As far as I'm aware, every truck has a Whelen siren system. Not sure what model or version though. They had to be able to do it relatively quickly though since they're a rescue truck so it couldn't be an all day thing. Any ideas?