[Q] System Audio topic

So I flashed CM12 to my 2013 Nexus 7 and it used the audio for the keyboard that kit kat uses and I hate the way it sounds. So I went to /system/media/audio/ui and replaced those files with with the ones from my friends 2013 Nexus 7 who on stock and now it makes no sounds. So I then downloaded stock image for my Nexus 7 from Google and extracted the system.img and took the sound files from it and placed them on my Nexus and it still won't make any sound. When I play the .ogg files on my computer they all work but when i play them on my Nexus only a few play like NFC sounds but things like Lock and Dock wont play.