adjust max possible volume in pulseaudio
The maximal possible volume level we can obtain from sliding the volume control to more than 100% is approx. 153% above the normal peak limit. Provided we had set the ALSA volume with alsamixer to 100 these 100% are the level above which audio will be clipped or distorted. This also will happen when amplifying to 153% with the slider.
Nevertheless is is possible to further increase this level by setting the sink level using the follwing command in a terminal:
pacmd set-sink-volume <sink> <value>
Replace <sink> with your sink name or sink index as given from:
pacmd list-sinks
The lower limit for <value> obviously is 0, a linear volume of 100% is a value of 65536, anything higher will be further amplified. A value of 512000 will thus lead to an overamplification of 781%.
This is a very crude method to amplify sound output of varying level as overamplifying will lead not only to clipping and ugly distortion but may also damage your speakers.
Therefore it would be a better way to normalize your audio output. See the following question on how to do this with pulseaudio:
- Automatically adjust the volume based on content?
I tried this command:
pactl set-sink-volume alsa_output.pci-0000_00_1b.0.analog-stereo 150%
and it was very helpful. One can change the 150% to any value.
Video Demonstration
I use
pactl set-sink-volume 0 100%
Where 0 is the sink number from pacmd list-sinks and 100% is the default unboosted volume. You can enter values above 100% to get audio boost (200% for example).