the Koss Pro\/4AA represent vintage design and super high quality sound reproduction . mind they need a few hour of ` break in ' before the full , rich sound unfold . and mind ... they be design in a different age , when maximal sound quality be everything . they be heavy , and you can not do anything but listen to music , while wear they . this be my second pair - buy the first in '78 and litteraly play they to shread . Trien modern one , expensive one ... but the rich sound just be not there . so i be back to Koss Pro\/4aa .