I had a semi-low serial numbered K701 (in the 4200s) before replacing it with the K501. I think K701 is trying to be too many things to too wide of a demographic. I thought K701 sounded great when I first got them (boy, did those glass breaking sound like they were next to me). However, over time I have come to realize I didn't reach out for K701 when I was actually listening to music. Not saying K701 is not musical, I just preferred other cans for the particular types of music I was trying to enjoy at any given moment.