Metal composite diaphragm has the apparent advantage in sound transmission and is made for the high quality audio systems. The metal-coated layer of the diaphragm is faster in high frequency transmission which provides multiple details. The whole diaphragm presents excellent performance including powerful bass and stability of sound. Sound waves produced by the diaphragm are reflected by the wall of the sound chamber back on to the diaphragm, interfering with sound restoration in the headphones. The dual damping system in Mi In-Ear Headphones disperses the reflected sound waves and reduces their effects on the diaphragm, giving you a purer audio experience. Everyone deserves access to high-quality audio experiences. Xiaomi is committed to making that access a reality!