Sound improvement in Lenovo a7000 and other devices

You can increase the sound of any android if you can get into engineering mode.
If you're using gravity box ,the option has been given to the bottom of the UI.
You can also use apps like "mobile uncle tools", "engineering mode app" etc to go into engineering mode.
Instructions:
1) Open engineering mode.
2)Scroll to left and come to "hardware testing".( in gravity box)
3) Open "audio"
   Now you will see different audio settings under "audio". You have to modify the first four categories for all-round audio improvement.
a) Normal mode.
b) Headset mode.
c) Loudspeaker mode.
d) Headset_loudspeaker mode

Open each one of them and set the max value to 160.
See the screenshot