Engineered for the serious pro audio user, the U15 offers a radical loudspeaker cabinet design utilizing the patented Unity Summation Aperture Horn Technology, which was invented by loudspeaker designer Tom Danley and licensed from Sound Physics Labs Inc. The U15 provides remarkably even high / mid frequency distribution from the 60º x 60º horn assembly. The combination of the conical, constant directivity horn, 15" new technology Neodymium woofer and Yorkville's unending attention to details, right down to the ideal trapezoidal shaped cabinet has yielded an extremely versatile product. The U15 Unity horn combines a single 1 inch throat (1.75" diaphragm) compression driver with three 5-inch ceramic magnet midrange drivers on a single highly efficient conical horn. This combines high and mid frequencies driver components in a single 60º x 60º conical horn that produces frequencies from 300Hz to 20kHz. Added to all this is the ultra lightweight Neodymium 15 woofer to complete the package. The U15 can be easily bi-amplified by way of a switch on the rear jackplate, or used with any élite series subwoofer for extended low frequency support. The UP15 Unity processor, designed specifically to optimize the sonic characteristics of the U15 has also been developed to ensure trouble free, plug-and-play full range or Bi-amp operation with or without a subwoofer.