[Q] No media at all topic

Hello i really need some help. i have a samsung galaxy s4. when i got it was very slow and everything kept freezing up. when i downgraded it to jelly bean 4.3 it works perfectly, except for the media. i cannot hear any sounds, play any videos, record anything and when people call me the phone becomes slow and i am not able to answer. i had these same problems while it was running kit kat as well.