The Federal Signal Rumbler®, intersection-clearing system, demonstrates the longstanding commitment to continue as the technological leader in warning sound, Siren development, and operator safety. Improves Intersection Warning Effectiveness-The Rumbler introduces a revolutionary new concept to audible warning. This system has the ability to interact with 100/200-watt siren amplifiers and provide secondary, low frequency duplicate tones. Low frequency tones have the distinct advantage of penetrating and shaking solid materials allowing vehicle operators and nearby pedestrians to FEEL the sound waves, and perhaps even see their effects through a shaking rear-view mirror. Secondary System with Built-in Safety-In addition to the primary siren amplifier and speaker, the Rumbler adds a secondary amplifier. This gives the system the ability to sense the currently enabled siren tone signal, reduce the signals' frequency by 75%, and amplify the sound through a pair of high output woofers. The systems' timer allows the tone to sound for 10 seconds, and then automatically shuts off. The result is a highly effective backup emergency tone, especially when transitioning hazardous traffic intersections. The Rumbler is particularly effective when used in dense urban environments with heavy vehicle and pedestrian traffic. A complete Rumbler intersection-clearing system consists of an amplifier, a timer, two subwoofers, and vehicle specific mounting hardware(sold separately). This system can be paired with most 100/200-watt emergency siren amplifiers and the Rumbler system is most effective when used as an intersection-clearing device where heavy vehicle and pedestrian traffic is present.