I don't have a problem with dual sirens. In fact, I find their effect to be a positive thing, since you can never be sure which tone is going to punch through to the other drivers' consciousness. If you're running both simultaneously, you've got your bases covered. What I do have a problem with is what Dan just referred to, which is this attempt to "orchestrate" the effect, especially on the part of the driver. The last ambulances I spec'd out had two sirens. But they were both controlled by one single on/off toggle switch. No knobs. No buttons. No levers. Just one switch that turned them both either on or off at the same time. No fumbling while driving. No playing with the tones. No distractions. On or off. Period. It's not a toy. It's not a fashion accessory. It's not a job benefit or a way of life. It's a tool, just like a gun. Don't screw around with it. Just use it when necessary, and forget about it otherwise.