Increase Sound level

Using the following command in terminal, you can set sound level as you wish:

pactl -- set-sink-volume 0 150%

In this case we have set the volume of the sink #0 to 150%.

Now, if you want to set this setting as default at startup, add the above command in /etc/rc.local file. You can use sudo -H gedit /etc/rc.local to open an edit this file:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

pactl -- set-sink-volume 0 150%

exit 0