I got a pair of AKG K 271 mkII headphones awhile back and they shipped fine, had absolutely no problems. However. one day I picked them up and plugged them in to my laptop and they seemed to be out of phase? Anything that was in the center of the audio (vocals, bass, some drums), was reduced in volume to the point where you couldn't hear it at all. Usually left/right guitars play fine and I can hear the cymbals as well.
However this is only when I plug them so the tip of the TRS connector makes contact with the back of the laptops (or any other devices) headphone jack. If I pull it slightly out, the volume level is back to normal.
Edited by Zaprowsdower - 1/7/14 at 1:55pm