The S-Series delivers amazingly high performance for this class of speaker. They boast the world’s first use of a CFRP diaphragm (Carbon Fiber Reinforced Plastic), which has the ideal balance of hardness and light-weight, for extremely clean and accurate sound. They also feature a larger voice coil than previous types for higher driving power, and the same HAMR surround as used on the X-Series. Peak Power: 170 Watts RMS Power: 55 Watts Frequency Response: 80 Hz - 22 kHz