Pros: Spacious sound stage; realistic vocals; high level of detail; lightweight and comfortable for long sessions;
Cons: Can be a little on the cold side
I've owned these for the best part of a month now and have done some extensive listening with them both in extended listening sessions of several albums and of comparative listening sessions with with my HD650. I feel I am ready to comment on the qualities of these phones.
I had always intended to put these and the HD650 against each other and sell one, as I had thought it would be an indulgence to keep two expensive open circumaural home-listening phones. The problem I have found (and it's a good problem to have) is that the are fantastic companions. Any type of music the HD650 does not do so well with, the K702 shines with and where the K702 seems a bit too formal and cold, the HD650s warmth is a perfect tonic. I'm keeping both.
Formality is really the term I would use to describe these phones. They are polite, analytical and are certainly revealing of a track, with details not just presented but presented with a crispness and accuracy that is a joy to hear. Don't bother listening with anything but high quality encodings though, as it will show up the wrong kind of detail just as clearly.
The AKG K702 have less bass than most of my other phones, but still presents more low end than, say my Phonak PFE or MS2i with bowls rather than flats. The bass is of an exceptional quality, impact and speed. The mid range is beautiful and airy, especially where it comes to female vocals which sound sometimes unnervingly real and the treble is crisp, if a little cold.
The real star of the show when it comes to the K702 package is the sound stage. I was worried I would be put off by its size as many complain of it being unrealistic. Well, it's really not that big, but it does offer the space you need to really delve into a song, picking up on this and that instrument and then mentally stepping back to hear the whole track as one.
It's sound stage and level of detail really make these phones perfectly suited for my classical music and my jazz and my electronica and works very well with layered rock/alternative music such as Radiohead, Captain Beefheart and the Magic Band, Frank Zappa, the last two Joanna Newsom albums and that sort of thing. That isn't to say it doesn't do a great job of presenting rock, pop, reggea and simpler folk as well as it is certainly pleasant, but for these warmer and simpler types of music I find myself switching to the funner HD650 with its more intimate sound stage.
Comfort with the K702, for me, is a major plus. I understand a lot of people have big problems with the bumps on the bottom of the headband. Pressing them with my fingers I can feel they aren't comfortable, but I have plenty of hair and do not really feel them. The 3D form cut velour pads seem to have been designed for the shape of my skull and compared to the HD650 the lack of clamp is quite a relaxing experience. I can wear these for hours on end and often forget I am wearing them.
If the AKG K702 were my only headphones, I might find their genre range a bit limiting, I might find myself wanting a bit more bass with my reggae and hiphop and a more intimate sound stage with my rock and folk. But as a part of a varied collection with the HD650 and MS2i as the other two main home phones I find I have a great set of options to cater for every mood and genre.
The AKG K702 has filled in some gaps for me; has given me a classical and jazz listening option that can seriously compete with speakers, a natural home for aphex twin and a sound stage that brings the best out of some of my more complex rock music as well. Add to this it's almost unnervingly realistic reproduction of female vocals and it really does justify its price.