Featuring an internal surround reflector, the Sennheiser HD 558 headphones are able to generate an extended spatial sound field for a listening experience that immerses you during music and movies. Its advanced Duofol diaphragms are delivering transparency and minimal distortion, while the optimized, field-strengthened neodymium ferrous magnet systems yield a convenient dynamic response. The headphones have a frequency range covered of 15 Hz - 28 kHz. With 50 ohms impedance level and 112 dB sensitivity, they come with a 3 meter long cord and weigh 259.97 grams.