Far from portable, the K 702 is a very large over-the ear set of headphones, with extra soft velour covered cushions. The real leather/metal wire headband distributes the weight of the 'phones evenly across your head, which means you can wear these headphones for hours at a time and they'll remain nice and comfy. And the headband is clearly marked "L" and "R" so you'll never make a mistake when donning the headphone. The K 702 is hand assembled and tested in Austria, which shows in that build quality, fit, finish, and durability are all first-rate. However, AKG does not include a storage case in the package--a bit of an oversight in this price range.
On the technical side of things, the K 702 features flat-wire voice coils to maintain low distortion levels, even during high-volume listening. AKG claims its patented Laminate Varimotion diaphragms allow the K 702 to produce out-of-head imaging, and we agree. These headphones really deliver on that front: depending on the quality of the recording you're listening to, the sound appears to come from farther away than it does with most headphones.
During testing, we plugged the K 702 into an Onkyo TX-SR805 for most of our home listening tests and compared the cans with our reference Grado RS1 headphones ($695). Both are excellent, but it was readily apparent that the K 702 sounded more speaker-like. Norah Jones' vocal and piano on her "Come Away With Me" CD seemed to come from outside the headphones--we even had to check to make sure the speakers weren't accidentally turned on. The RS1 sounded closer and more immediate, and the piano's transient attack was more life-like; by contrast, the K702 put the piano farther away. The clarity was extraordinarily good, and never aggressive or thin. AKG engineers gave the K 702 the perfect balance of resolution and smoothness. (Also, the K 702's pillowy ear cushions were far more comfortable than the RS1's harder foam cushions that rested directly on our ears.)
Next, we watched a few movies and the K 702's spatial qualities came to the fore. On the "Mad Men: Season 1" Blu-ray, the sound of the large offices, with dozens of IBM typewriters clacking in the distance, was especially convincing. We could even hear murmured conversations of executives behind closed office doors. The Grado RS1's bass went a little deeper and was more impactful on the "House of Flying Daggers" DVD's circle of drums scene. That is, the drums were more realistic sounding with the RS1, though the K 702's bass and dynamics were still quite good. Again, we preferred the K 702 for its open, spacious sound, which was even more evident with movies than it was with music.
We finished up with the K 702 plugged into a 15GB iPod, and the sound was excellent. True, the iPod didn't have the oomph we got from the Onkyo receiver, so the sound balance was more midrange, and the bass didn't feel as deep. Then again, the K 702's size might rule it out for portable use. But it's still one of the best-sounding set of headphones we've ever heard with our iPod. Our Ultimate Ears UE-10 Pro in-ear headphones ($900 MSRP) can make more bass and have a warmer midrange, but the K 702's clarity, and open, out-of-head sound staging has it all over the UE-10 Pros. (It's worth noting that the UE-10 Pros can play much louder over an iPod than the K 702 can.)
Sure, the AKG K 702 is an expensive set of headphones, but the sound is near state of the art, only bettered by much more expensive headphones like the soon-to-be-released Sennheiser HD800 ($1,400). The K 702's creamy soft ear pads are so darn comfy it is easy to forget you're wearing headphones. In the end, we highly recommend this cushy, sweet-sounding set from AKG.