"With more powerful amplification such as the Grace m902, the HD650 improves on the bass clarity as it also picks up some speed. (I don’t mean speed as in transients, but rather, the ability to carry the pace with fast-paced music). It even carries the pace quite well with aggressive music such as Muse’s Uprising or Rage Against the Machine’s Evil Empire. With the Beta22 and balanced drive, the HD650 is even quicker, and improves the bass texture even more. However, at the end, the speed is still a tad behind the K701 and bass texture is far behind the DT880. So, in that sense, the HD650 is not the best headphone to choose if you like very fast Rock or Metal, but it should be fine for stuff like U2, John Mayer, the Beatles, and such. The DT880 actually has an ideal speed, pace, and control for such genres, but its excessive treble will cause serious problems as most of these recordings tend to be quite hot on the treble. As it is, none of the three headphones actually work for fast Rock, and we need to be looking at the Grado RS-1, Audio Technica AD2000, or the Hifiman HE-5 for that"
"With more powerful amplification such as the Grace m902, the HD650 improves on the bass clarity as it also picks up some speed. (I don’t mean speed as in transients, but rather, the ability to carry the pace with fast-paced music). It even carries the pace quite well with aggressive music such as Muse’s Uprising or Rage Against the Machine’s Evil Empire. With the Beta22 and balanced drive, the HD650 is even quicker, and improves the bass texture even more. However, at the end, the speed is still a tad behind the K701 and bass texture is far behind the DT880. So, in that sense, the HD650 is not the best headphone to choose if you like very fast Rock or Metal, but it should be fine for stuff like U2, John Mayer, the Beatles, and such. The DT880 actually has an ideal speed, pace, and control for such genres, but its excessive treble will cause serious problems as most of these recordings tend to be quite hot on the treble. As it is, none of the three headphones actually work for fast Rock, and we need to be looking at the Grado RS-1, Audio Technica AD2000, or the Hifiman HE-5 for that"