From the Quad BA system, integrated magnesium inner housing and an optimized sound path, the structure of the IER-M7 is made from high-quality parts. So you can trust them to make you sound your best. Evolve your musical expression through accurate and detailed monitoring with Quad BA system. Sony's original T-shaped Armature directly drives the diaphragm for more linear motion and clean, faithful high notes. Sony custom audio grade film capacitor in the cross-over circuit delivers much lower distortion. The audio grade capacitor of the IER-M7 delivers fine detail sound. Plus, audio grade solder also helps to minimize any loss in signal path. With an integrated magnesium inner housing and optimized sound paths, the IER-M7 headphones deliver balanced tones that enrich your musical expression. The BA units are held firmly in high-rigidity housing. This helps to eliminate vibration and keeps sound clear and clean without losing even a micro nuance of sound. A wide and short sound path made of brass reduces frequency peak and dip, to give a monitor sound you can rely on for critical listening accuracy. The IER-M7 are designed to stay firmly in place with a snug fit for all ear sizes. With a firm fit and optimal housing shape, each earbud stays in the right position, even while moving on stage.