SONY Stereo Headphones MDR-XB700 | Extra Bass Closed Dynamic (Japan Import)-B... 50mm driver units: Exclusively engineered by Sony, the extra-large 50mm Extra Bass diaphragm driver units accurately reproduce ultra-low frequency sounds and deliver dynamic, deep bass reproduction. Direct vibe structure: Built with a direct vibe structure to ensure high audio fidelity, the Extra Bass headphones feature a tightly sealed acoustic design that allows for a high level of sound isolation which reproduces powerful and extended bass sound. Closed, dynamic design: Experience the ultimate in comfortable listening with the Extra Bass headphones' over-the head, around the ear circum-aural design. The drivers inside the ear cups are angled parallel to your ears to not only reduce pressure, but increase comfort and deliver an unbelievable listening experience. King sized ear cushion: Providing more than exceptional sound, the Extra Bass headphones feature ultra-thick, pressure-relieving ear cushions for supreme comfort and better acoustic performance. Each earcup measures 2.0 inches in thickness and 4.3 inches in diameter. The flat and seamless, cloth-lined headband delivers enhanced wearing comfort. Optimal sound quality: Sound leakage and a loss in audio quality are minimized thanks to a sealed acoustic design. Additionally, the MDR-XB700 headphones have an exceptionally wide frequency response from 3-28,000 Hz.