BMS 4538 is a powerful 1" professional compression driver that delivers superb sonic quality at a small package. The unique BMS annular diaphragm together with the patented radial phasing plug achieve very high sensitivity and linear frequency response up to 30 kHz. The sound of the BMS 4538 has an exceptional dynamic range and produces even the most complex music signals with depth and definition. The BMS 4538 - 1" compression driver is designed for a wide variety of applications including small to medium high quality professional reinforcement systems and stage monitors. The 4538 offers all the benefits of the patented BMS compression driver design, but at much reduced cost.