Sennheiser HD 600 Open Back Professional Headphones - Black Contents: Come with accessories in retail Box. New Opened Box Condition. Product Information The Sennheiser HD 600 Headphones feature an open circumaural design, aluminum voice coils and optimized magnets for producing clean stereo sound. These black headphones offer a frequency response of 12 Hz to 40,500 Hz. For a rich dynamic audio response, it incorporates neodymium ferrous magnet systems. Audio transparency is delivered through the open metal mesh grilles. Additionally, th