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An introduction to computer audio
Volume control
Using the volume control of your media player can result in a distortion.
One easy example is applying volume control. If you change the volume to 90% for example, the software will multiply all the digital audio data by 0.9. The result is rarely an exactly 16-bit word, just like dividing regular numbers often results in non-integer numbers. It usually has a remainder...which will require more bits (digits, or decimal places in regular numbers). If the data path is limited to 16-bit, the remainders will be truncated. That's analogous to dividing 10 by 3, and having a result of 3. With extra digits available, a more accurate result of 3.333... can be achieved.
If you have a 16 bit source and a 24 bits audio device, padding 8 bits does the trick.
This allows for 6x8= 48 dB reduction before the actual bits are mangled.
A simple solution is to set the digital volume control to max. No multiplication is applied.
Combine this with a DAC driving the power amps directly (more and more pre-amps are eliminated from the setup) and you have a problem if the DAC doesn't have a volume control.
A simple passive attenuation can solve this problem.
Next question: does analogue volume control induces distortion?
Why is attenuating the signal in the analog domain better than the digital domain?
I realize you are throwing away resolution in the digital domain, but in the analog domain, with a standard preamp, you are raising the noise floor by excessively amplifying the signal, then attenuating that signal which doesn't attenuate the amplified noise. You are not necessarily raising the noise floor with a passive attenuator, but you can very negatively impact dynamics with a passive attenuator if it is driving a low impedance amplification load.
If digital attenuation was implemented in with 32 or 64 but math, is it necessarily worse than analog attenuation? The reason I ask is because my ears tell me that one problem is just being replaced with another when comparing digital to analog attenuation.
