Welcome To The Siren Board! I am a siren enthusiast that lives in Maryville, IL. Our town's siren system is composed of 2 Whelen Vortexes. One of them has an ESC-2020 560Hz Electronic Controler. The other one, that I live the closest to, has an ESC-864 Digital Controler. The Whelen Vortex that I liv...