Assertion: large subwoofer | /r/HasProperty | driven by racks of 500 watt amplifiers
Facets:
Source sentences:
text: Initially installed in 17 U.S. theaters, the Cerwin Vega "Sensurround" system used large subwoofers that were driven by racks of 500 watt amplifiers, triggered by control tones printed on one of the audio tracks on the film.