To me it was sibilance. Soundstage was average. And yes i have 3 pair of zst. 2 rainbow and 1 carbon. Never like them. Zs3 was different. On the first time i try it. It blows my mind. This is the earphone that has all aspects nearly perfect. Soundstage, treble was done right, mid and bass has enough quantity. Ive tried senfer dt2 plus and i can say zs3 was better than dt2 plus with triple driver.