I personally think that negative comments about a headphone say more than positive. So, I want to take this opportunity to state some bad things about all of my headphones. Here we go
K701 (gets the bulk and some of the harshest of the complaints because I have been using it the most):
1. Has un-differentiated, untextured, and oddly bloated bass with poor extension. Not that there is that much of it, but what is there is low-quality. Its bass generally comes in two main flavors: boom and thud.
2. Soundstage is 3-blob with poor imaging. Instruments in certain parts of the soundstage (sounds that are in just one channel, usually) only get partially through, resulting in horribly "un-imaged" (sic) sound. Other headphones have no such problem.
3. I usually get absolutely no sense of "being there" from these headphones, being all too aware that I am listening to a recording.
4. There is a treble spike that can result in harsh sound.
5. Music is put second to detail, of which there is not that much. Unmusical and not very detailed, in other words.
6. Sound can become very muddy, with no instruments standing out, resulting in a wall of crappy sound with no music to be found within.
7. Instrument separation isn't as good as people say, with some instruments being lost in recordings other headphones have no problems with.
SR225
1. Poor-quality treble in certain areas, with cymbals and such frequently sounding like nothing but a poorly-rendered thssssss sound.
2. Too much treble.
K81DJ
1. Zero soundstage.
2. Too-strong bass.
3. Lack of detail.
KSC-35
1. Bloated, bloated, bloated overpowered bass. Makes those idiots with the giant car subwoofers feel right at home.
2. The "front" part of the soundstage is separate from the left and right areas and has absolutely no depth.
HD595
1. Very muffled sound, like all the air has been choked out of the music. Basically makes this headphone unlistenable for me.
MX400
1. It is an earbud, thus the sound is absolute crap, period. Worthless.
Every headphone has crappy traits. It is about finding the headphone which has the crappy traits you hate the least.