Find the overall sound volume and audio clarity a bit low on on your Sony Xperia Z Ultra? Here are steps if you wish to do so. First change the value of mixed_paths as follows:
Handset Voice 94
Headphone Voice 93
Handset 93
Speaker 93
Headphones 93
Speaker and Headphones 94
Go to settings > apps > audio settings and clear the data. Also clear the data of walkman and now download the walkman app from here. Open the walkman app and you will find better sound volume and audio clarity. If you want to experience some bass, set the equalizer to:
400 to +3
1k to -3
2.5k to +2
6k to +6
16khz to +10
clear bass to +10