Price Match Guarantee Sennheiser HD 650 Audiophile Hi-Res Open Back Over Ear Headphone In the HD 650, audiophiles will experience truly unique natural sound. With sound this good, long concerts in the comfort of your home are a certainty, so the HD 650 also sets standards in comfort and convenience. The HD 650 is a genuine masterpiece, which will satisfy even the most demanding listener. Putting on the headphones and using them- Put on your headphones and then pull the ear cups down until they rest comfortably over the ears. Make sure you have them the right way round by observing the "R" (right) and "L" (left) markings on the ear cups. For optimum sound quality, ensure that the ear cups are not covered. Product Highlights: Specially designed acoustic silk ensures precision damping over the entire frequency range and helps to reduce THD to an incredible 0.05 percent Improved frequency response is 10 39,500 Hertz ( 10 dB) Hand selected matched driver elements; Highly optimized magnet sy