The HD 650 from Sennheiser are reference class stereo headphones designed to deliver a true audiophile experience with open, natural sound. Specially developed acoustic silk was used to provide uniform attenuation over the entire area of each ear-cup. The lightweight aluminum voice coils ensure a remarkable transient response, while the full range drivers offer a frequency response of 10 Hz to 39.5 kHz. Great care was taken to ensure the headphones are comfortable with their elliptical design which naturally adapts to the shape of the ear.The HD 650 utilizes a 3m detachable cable made from a highly conductive OFC copper with low handling noise and low structure-borne sound sensitivity. The headphones can be used with high output mobile devices and excel with high quality stationary hi-fi components, such as SACD, DVD-A, and CD players. The HD 650 ships with the detachable cable and 1/8" to 1/4" adapter.