Last week I bought phone SE w910i from a mobile network store and the first thing I noticed is that the sound quality is poor. I thought the headphones are weak(and they are) but then I tried comparing this phone with my sister's Sony Ericsson w200i with the same headphones and same track. The sound from w200i is amazing with smooth Mega bass EQ, the bass on w910i is horrible! Is it possible that the soft may be damaged because the phone is branded by the mobile network? I tried to update the phone, but no changes in sound. If I debrand the phone and bring back to "factory soft" will it sound properly? Or what happens if do a master reset? Have anyone experienced such problems with this phone? I'm thinking to switch phones with my sister 