Music sounds great!.But the entering calls sound horrible,Ican't

The volume setting on your phone affects the volume as well. Turn the phone up more. If this has already been tried or does not work the keep reading. I believe the call sound comes only through a front speaker (maybe the right front...not sure but I can check on this). If the music seems like it sounds good (with all the speakers) there might be a slim chance that the one speaker that plays the call is not working well. Use the fader and balance setting to switch to each speaker one by one and play sound through it (preferably a commercial with people speaking). See if one of the front speakers is blown or at least does not sound good for voice. This would mean replacing a speaker front set.