M6 has horrendous sound out of the box and are not listenable at all without heavy equalization - you'll probably not even recognize familiar tracks, it sounds *that* bad. Seriously. Extremely exaggerated bloated bass, non-existent middle - this converts what was in the original "a vocalist with some drums / bass guitar etc. in the background" into "SWAT is breaking my door and somebody is whispering a song". However, if properly equalized, they sound surprisingly good for headphones at their price level - with well controlled bass and good details, I'd say about $50 good. :-)
They are sweat resistant, so IMHO they are a good inexpensive option to use in gym *provided your player has equalizer* - this is how I use them.
They are sweat resistant, so IMHO they are a good inexpensive option to use in gym *provided your player has equalizer* - this is how I use them.