Well...My reply assumes lossless or extremely good lossy, such as 320k LAME.
These phones were headphones I could not stand for a long time, I quite hated them. They were just too bright. I gave them a 2nd chance recently when I reconfigured my system, as well as upgraded my amplification. I am beginning to have to eat some crow, because most of the things I sighted as problems are simply gone. What did not suprise me is how less fatiguing they are, and that is because I am using more tubes in my setup, but what got me was the quantity of bass that just was not there before, I would have never considered these for electronic music production of any sort, sampled or produced. Today, I am very happy with them, and consider them to be a great headphone for produced electronic IDM, and sample based electronic productions, whether it is for hiphop or not, because they do very well when it comes to getting back to that original sample... like if you could take a xerox or two of your copy of a copy of a copy of a copy.
I have produced two electronic music albums that used a combination of samples and generators/synths, and of course VST effects/automation. I often used a singe wave shape, looped, as a generator, since it was an easy way to save some CPU, but I also would take string and flute loops and put them through processing, offeset severl of them layered for a fat harmonic sound, and so I know all about profuction methods, though I rarely sampled more than a single instrument, and I often would construct my own samples from combinations of the attacks and decays of different percussion elements, I have to say that these do a very good job at reproducing the 100% digital generated synths and effects as well as sampled instruments, and their complex harmonics as several offest streams would interact, even, with each other, with loads of reverb then EQed, then sampled and done again... most cans can't capture a lot of what I was trying to do, but these are one of the most least expensive sets that can. Their performance on complex IDM is to be praised, for example Autecre, both old school from 1994 and Confield (to me, their peak), to their most recent record. The first track on Confield has the punch and then the beauty of the synthetic notation that decays slow slowly later in the song. When it first comes in, I get goosebumps.
I think the solid build lends a lot of what makes these a good choice for these genres, and their accuracy w/ relatively flat response makes them great fr symphony music. I always thought they sounded goot with orchestra pieces, but for more than that, to me they were just too ear shredding, but it is amazing what some new components can do to open up a more broad set of headphone options. I prefer them as I do my other headphones, with my Mackie mixer taking in the source, and then going out to the Grace 902, but back when I didn't have as much synergy with my source and the Mackie, or when I didn't have a high end headphone amp (either the console monitor port or a Presonus HP4), I was so very close to selling the Shure 440s.
If you want to get the most out of a wide range of music with complex harmonics, and listen to lossless or very high quality lossy, such as 320k LAME, then these phones aren't going to do a bad job of being true to the source material, as well, they will sound good enough to sit back and enjoy the music. I just don't see them as a headphone for a DAP. I still maintain they are a can that someone into music production in some way, maybe not even in a serious way, but respects the art of sound engineering, would enjoy. They are definitely made for the studio first and your portable, like an ipod, last.
