Can I increase the sound volume above 100% in Linux?

Have you tried changing the various channels through alsamixer? (run it from the terminal)

You may also want to check your PulseAudio settings. There's a GUI front-end package called pavucontrol that allows you to easily change these settings.

The answer is yes you can, install pulseaudio, on debian like for example

sudo apt-get install pulseaudio pavucontrol

Increasing volume using gui

just open pavucontrol and scroll the volume bar

Increasing volume programmatically

Use the command below to increase the audio

pactl -- set-sink-volume $SINK +110%

where $SINK is the number of the audio channel, it can be 0, 1, 2, N. To check the available channels you can use

pactl list | grep 'Sink'

I,ve made the following command to automatically detect the audio channels and increase the volume by 3%

pactl list | grep -oP 'Sink #\K([0-9]+)' | while read -r i ; do pactl -- set-sink-volume $i +3% ; done

Make sure to restart you computer after install pulseaudio

I have raised audio volume above 100% using gnome-volume-control. However, this only works from the Audio Settings dialog and if you ever change the volume from the applet it drops back to 100% and won't go above it again.

Never tried it in KDE.