I'm looking to buy either Audio-Technica ATH-M50 or Sennheiser HD 558, and desperately need a suggestion about which one is better for me.
I often listen to rock & metal genre, and occasionally electronic.
I prefer open-back headphones (that's why discovered HD 558 at first), but after a couple hours of Googling I find that many reviewers highly appreciate ATH-M50's quality for its price.
One more thing, is it necessary to use a headphone amp for those headphones? is it will drastically improve the sound quality?
I'm using Creative X-FI external soundcard and can't find any related info on how good it is for headphone playback.
P.S. I'm very welcome if there's a better alternatives for $100 - $200 price range headphones.
A Grado SR 225i may be better for you than the other two, but that depends in large part on the sound signature that you are seeking (you need to tell us). These are three very different sounding cans. There are more options of course, like the Ultrasone HiFi 780...
Since you mentioned an open and closed can, I have to assume that you are OK with either design.