For people like me who do not read instructions and may wonder about the disastrous stereo reproduction: The headset has a small switch on the right shell to turn around him Mono / Stereo. :) The switch was adjusted with me in the factory setting to mono playback.
The headset was an impulse purchase. The mechanical quality is ok, the sound of my ears. Weak bass, center-weighted very tiring, heights scarce. Sounds unpleasant.
Price / performance may be fine, but the bottom line is this is not a good headset.