How to obtain screen brightness control
sudo gedit /etc/default/grub
Add acpi_vendor=backlight , as follows:
GRUB_CMDLINE_LINUX_DEFAULT="splash acpi_backlight=vendor"
GRUB_CMDLINE_LINUX="acpi_backlight=vendor"
Then update GRUB
sudo update-grub2
Then reboot
How to gain a full Beats™ audio experience
sudo gedit /etc/modprobe.d/alsa-base.conf
paste this to the end as a new line:
options snd-hda-intel model=ref
reboot and enjoy improved audio!
After that enable brightness keys in Power Management like on the picture
taken from here