The top-line model RH600s use a specially designed, high performance driver with a thin, responsive 40mm diaphragm coupled with a high output neodymium magnet and sophisticated circuitry to provide true "reference quality" audio. Its ambient open-ear design with special acoustic mesh fabric ensures clear, transparent sound and a comfortable listening experience. The RH600s also feature a very wide dynamic range and a linear frequency response from 20Hz to 22kHz for accurate, balanced audio reproduction.