Over the last few years you've probably noticed more and more people using "studio headphones" out in public, and recently I even saw one brave soul use the openheadphones in the turbulent bowels of New York's subway. AKG has seemingly picked up on this trend, too, and has added a three-button remote to the existing K550 headphones in the name of portability, resulting in the K551 model.
Design and features
Compared with headphones that are designed for portability like the -- and in a lesser way the -- the K551s' hi-fi roots are obvious. These are very large cans and feature enormous, supra-aural earcups. If you choose to wear them outside, you are truly making a statement: "I am an audiophile, and I do not bow to your dictates of fashion." Witness the baby-blue(!) headphone cord and the white color scheme, and when I asked my colleague Jeff Bakalar to score them on a scale of 1 to 10 for potential "douche factor," he rated them as "a hot 7."
However, if you like to be a little more invisible when in public, you might prefer the silver/black version with a black cable. In either color choice, it's a short cable, though -- only 3.6 feet -- and if you want something more suitable for home use you should try the cheaper, hi-fi version of these headphones, the K550s.
The build quality of the K551s is excellent and they feel very sturdy. The swiveling earcups do fold flat for carting them about; no carrying case is supplied. Thanks to the swiveling nature, you might need to adjust the earcups to get a good fit; otherwise you might find an extensive loss of bass response or get some intrusive street noise.