Windows 10 Volume Settings

[Spuriae]

Windows users are familiar with the volume steps at low volumes being too large, and the ones at high volumes being too small.

 

This data was taken from a Gigabyte Motherboard and verified with an HP laptop, so it is not hardware-specific. All of the output ports, and all of the Realtek "amplifier" settings, produce the same curve.

 

The highest volume settings don't just feel imperceptibly small; sometimes they're literally not there. There is zero difference in output level between 96 and 100. Similarly, the difference between levels 2 and 6 (11dB) is greater than the difference between levels 50 and 100 (10dB).

 

Repeating the measurement from the output of a Meizu Hifi DAC and Tempotec Sonata HD II, two external devices that are controllable with Windows 10 volume control, produces very similar (but not identical) curves.

The external DACs vary slightly from the default Windows 10 values but otherwise follow the same curve. Due to both of the external devices only changing volume in 0.5dB increments, they don't follow exactly the same curve. Interestingly, the Meizu DAC has a slightly lower minimum level than the default curve, though that doesn't make the overall result any better.

 

Curiously, the Windows 10 volume taper doesn't correspond to a linear volume control. The easiest way to implement a volume control is linearly (i.e., halfway on the volume control corresponding to halfway in terms of volts, but not decibels).

This turns out to not be the case (measured from ES9270 output, voltage level not calibrated so values are off by a scalar factor). The Windows 10 volume is not linear with the output level. Instead there seems to be some sort of weak power/exponential relationship. I'm guessing squared or cubed (both look pretty close when fitted).

Edited January 3, 2022 by Nimrodor
Graphs didn't display properly