whats the story behind the fire trucks and car alarms going off?
its the same concept as the guy with the sound system that u can feel from 40 feet away, the fire engine's diesel engine is very big, very powerful and because of those facts it produces lower sound waves kind of like a subwoofer, when it hits a certain rpm a frequancy is emited that a sensative car alarm interprets as a shock signal, normally it would be someone hitting the car but in this case its a low sound frequancy that your car alarm doesn't like, to fix it dampen the sensativity of the car alarm
