Volume control question

[ironwolf60]

Is there any difference in audio quality between

Windows volume 20% DAC Volume 50%
Windows volume 100% DAC Volume 15%
?

In the first case its possible to control volume with keyboard (assuming not using ASIO).

 

[Keith_W]

If the volume control of both is linear, example 1 is louder than the 2nd so of course it would sound different. However, I assume that your question is whether it is better to control the volume via Windows or via the DAC, in which case the answer is - it depends.

Digital volume control in Windows works by effectively reducing bit depth. Suppose you have a 16 bit audio file, each sample at 44,100Hz has a possible value between 0 - 65536 (2^16). Windows accomplished volume attenuation by multiplying each sample by a number less than 1, so if you want to reduce the volume by 10%, then the loudest sound is attenuated by (65536*0.9) = 58982.4. Every 6dB of attenuation reduces bit depth by 1, so if you are listening to a 16 bit audio file and reduce the volume by 12dB, you are effectively listening to a 14 bit file. In addition to reducing bit depth, it reduces the dynamic range and worsens the signal-noise ratio. Now, you can not send a value of 58982.4 to your DAC, so Windows rounds it down to 58982 resulting in a rounding error, which is effectively quantisation noise.

Third party convolvers or high quality audio playback software does not work like that, they are able to achieve volume attenuation without introducing the problems caused by Windows volume control.

Your DAC's volume control might work by: 1. attenuating volume digitally the same way as Windows, 2. Resampling audio and then applying volume control (superior), or 3. applying volume control in the analog domain. Options 2 and 3 are better than option 1, with option 2 the best of all.

Since I do not know how your DAC works, I am unable to answer your question as to which is superior.

 

[ironwolf60]

If the volume control of both is linear, example 1 is louder than the 2nd

both options sound exactly the same volume

Since I do not know how your DAC works, I am unable to answer your question as to which is superior.

its a smsl c200 (32 bits) with digital volume control, if its 1 or 2 don't know

 

[dualazmak]

Just for your reference (and interests),,,

I prefer "all in ASIO" routing in my PC-DSP-based multichannel multi-SP-driver multi-amplifier fully active stereo audio system; you would please find my latest setup here and here.

You can find my "historical" and "practical" background for my "all in ASIO" configuration here.

I now use JRiver MC as system-wide audio playback control center including the master volume control; if you enable JRiver MC's "internal volume", you can also use your keyboard's volume-up/down as well as stop/mute even under the "all in ASIO" I/O configuration.

Edit:
Furtheremore, if you would place mouse pointer around the volume control slider in JRiver MC, you can use also mouse wheel for volume-up/down.

I hope this diagram would be self-explanatory showing my master volume control by JRiver MC and relative gain control downstream.

 

[Keith_W]

both options sound exactly the same volume

its a smsl c200 (32 bits) with digital volume control, if its 1 or 2 don't know

I went to SMSL's webpage to see if I could find out that information, unfortunately it does not say. I would guess that whatever implementation the DAC uses should be superior to Windows volume control, which was probably designed with a different priority, i.e. low CPU overhead when changing volume. I would suggest keeping Windows at 100% and using the DAC to change the volume for the reasons I mentioned in my previous post. Alternatively, consider third party playback software like JRiver.

 

[AnalogSteph]

Is there any difference in audio quality between

Windows volume 20% DAC Volume 50%
Windows volume 100% DAC Volume 15%
?

In the first case its possible to control volume with keyboard (assuming not using ASIO).

As long as the DAC is set to output 24/32-bit samples and doesn't do anything fancy like switching analog output stage gain, both options should basically be equivalent. I think the Windows sound stack uses float32 internally, so precision should be a non-issue there... you should just keep enough output bits to avoid rounding artifacts.

Note, the usual caveats re: shared mode playback apply (e.g. keep application levels slightly reduced to avoid hitting the -0.1ish dB hard-limiter / match volume of audio player with ReplayGain, manage output device sample rate as required).

DAC volume should be set to still give adequate output on the quietest spots you may encounter once Windows volume is maxed out, then the latter can be backed off (you'll generally land in the 20-30% vicinity).