I have some Sony MDR-ED21 and the quality is brilliant, far better than the iPod ones, i did play really bassy songs and eventually the iPod ones blew up so i bought these and so far even on my computer stereo they seem realy good quality 
 
 
 
    * New Groove Shaped Earpiece provides wider frequency and better wearing comfort 
    * Bass Booster delivers strong bass 
    * Neodymium Magnet 
    * Sony acoustic twin turbo circuit 
    * Long bushing for comfortable fitting 
    * Thinner housing for comfortable fit 
    * Y shape cord 
    * 16mm Drive Unit Neodymium Magnet 
    * Pouch Supplied 
 
All for £18