I just purchased from a German web site (heimk***o-hi**) PFE012 for 79 euro, convinced by the reviews. Unfortunately I first listened to these headphones proved to be a total disappointment. The bass is completely absent, and the sound is metallic and shrill. In my opinion I have sold a defective pair of earphones.
Probably or the audio filters, the green, or the transducers are malfunctioning or are having problems.
Contacted the seller, they not only refuses to make is made according to the right of withdrawal, but warranty service without charge. Instead, it proposes to carry out a cleaning cost of 25 Euro, arguing that it is a health product and that, having used (only once) needs cleaning.
Which headphones did you use before? Remember that most low end 'phones sound very dark and muddy and adjusting your ears to a brighter sound takes some time.