Grado's ability to combine lightness with extreme rigidity and internal damping has been put to good use on the SR125. The SR125 features an improved diaphragm and voice coil design and UHPLC (Ultra-high purity, long crystal) copper voice coil wire. The diaphragms are put through a special 'de-stressing' process in order to enhance inner detail. An improved headband spring provides even greater comfort allowing the listener to relax and enjoy the fine tonal spread and balance. Bass, midrange and treble are all more open.