LOL. I would describe it as kind of a wierd hollow sound that's also kind of edgy. The K550 has a little bit of it (the pain part), but the MS1 and HD700 are much more closer to each other in terms of this effect.
If I recall correctly, the K550 sounded flatter overall, like nothing is wrong, and then BAM! The K550 didn't have that wierd hollowness at all times.
Some people may find this sonic effect exciting, fun, and clear. I find it wierd at best and painful at worst.