There is a debate why Windows has such bad sound, compared to Apple or small linux based streamers. Also there is a discussion which audio renderer or interface is best for playback. And I have to emphasize the playback specifically, because its no surprise that ASIO is great for audio mastering and recording of new content.
So I took the scientific approach...
1. I found 1KHz sinewave 24bit 192KHz samplerate 0dB Wav file.
2. I played it through various audio renderers in Foobar2000 and Media Player Classic - Home Cinema.
3. In every case signal went through optical SPDIF and landed in external DAC of NAD d3020v2.
I measured headphone out of the amplifier on my netbook which has lower internal noise than desktop PC. Output/Input were calibrated close to 0.0dB (using MPC-HC Default), while all software volume controls were on 100%.
Lets start with MPC-HC:
Default audio renderer.
There is a significant distortion around 1KHz. This is why Windows does subjectively and objectively sounds worse. As it was pointed out in a different topic, there is a workaround using Equalizer APO.
After applying Pre-amp -0.14dB in Equalizer APO...
the distortion is gone. This is a way how EQ APO may fix music and sound in games, which usually do not have any other option.
If you want to know why the workaround works and why the distortion even occurs read here:
https://www.audiosciencereview.com/...nding-the-windows-audio-quality-debate.19438/
Then there is MPC-HC internal Audio renderer, which is usually the only way how to access Wasapi Exclusive mode.
Results were identical for both exclusive and shared output. Sound is slightly less loud, by about 5dBs compared to Default. If you check the very top graph, the signal is not touching the boundaries as in most tests.
Then there is MPC-HC with 'MBSE Multichannel ASIO Renderer':
I expected it to be perfectly identical to Internal renderer, but there are two spikes around the 1KHz and harmonics seem to be slightly higher, but nothing audible. The main signal is much closer to 0dB thus slightly louder.
Also surprisingly, 'MBSE Multichannel ASIO Renderer' is a paid product for about 30 Euro.
Then lets go for Foobar2000 (v 1.6.5), 'Default audio renderer':
Interesting. Foobar applied its own volume correction by about 8-10dB, so the sound is not distorted. The volume reduction is even more noticeable when compared to the MPC-HC Internal renderer.
Then lets go for WASAPI Exclusive, with 24bit rendering:
Now the signal is much closer to the 0dB and harmonics are louder as well.
Lets check ASIO:
Identical to WASAPI Exclusive.
For Foobar 2000
Wasapi and ASIO plugins seem to operate in exactly same way in terms of audio output, however in current version ASIO plugin does not require manual switching between bitrates, but does not allow seeking.
Even Default renderer will operate without any Windows-related distortion, but at significant cost of volume.
For MPC-HC
its surprising that 'Internal Audio Renderer' reduces volume. 'Default' renderer performs as expected - introduced distortion when on maximum volume, but its easy to be fixed, the only downside is it operates in Shared mode, which is not optimal for playing DVD/BDs with 48KHz sample rate.
'MBSE Multichannel ASIO Renderer' acts as in Exclusive mode, does not reduce volume at all, even when it looks to introduce slight distortion around -100dB - nothing i should be able to hear with my setup.
Conclusion:
Foobar2000 'Default' renderer and MPC-HC 'Internal renderer' took away quite a lot of the volume, meaning you might need to increase the volume elsewhere.
Its actually surprising that there is any difference between different audio renderers. Even when there is little difference in terms of distortion, its actually quite interesting to see such different volume levels, as some renderers may take away 5 or 10dB of the dynamic range.
So I took the scientific approach...
1. I found 1KHz sinewave 24bit 192KHz samplerate 0dB Wav file.
2. I played it through various audio renderers in Foobar2000 and Media Player Classic - Home Cinema.
3. In every case signal went through optical SPDIF and landed in external DAC of NAD d3020v2.
I measured headphone out of the amplifier on my netbook which has lower internal noise than desktop PC. Output/Input were calibrated close to 0.0dB (using MPC-HC Default), while all software volume controls were on 100%.
Lets start with MPC-HC:
Default audio renderer.
There is a significant distortion around 1KHz. This is why Windows does subjectively and objectively sounds worse. As it was pointed out in a different topic, there is a workaround using Equalizer APO.
After applying Pre-amp -0.14dB in Equalizer APO...
the distortion is gone. This is a way how EQ APO may fix music and sound in games, which usually do not have any other option.
If you want to know why the workaround works and why the distortion even occurs read here:
https://www.audiosciencereview.com/...nding-the-windows-audio-quality-debate.19438/
Then there is MPC-HC internal Audio renderer, which is usually the only way how to access Wasapi Exclusive mode.
Then there is MPC-HC with 'MBSE Multichannel ASIO Renderer':
I expected it to be perfectly identical to Internal renderer, but there are two spikes around the 1KHz and harmonics seem to be slightly higher, but nothing audible. The main signal is much closer to 0dB thus slightly louder.
Also surprisingly, 'MBSE Multichannel ASIO Renderer' is a paid product for about 30 Euro.
Then lets go for Foobar2000 (v 1.6.5), 'Default audio renderer':
Interesting. Foobar applied its own volume correction by about 8-10dB, so the sound is not distorted. The volume reduction is even more noticeable when compared to the MPC-HC Internal renderer.
Then lets go for WASAPI Exclusive, with 24bit rendering:
Now the signal is much closer to the 0dB and harmonics are louder as well.
Lets check ASIO:
Identical to WASAPI Exclusive.
For Foobar 2000
Wasapi and ASIO plugins seem to operate in exactly same way in terms of audio output, however in current version ASIO plugin does not require manual switching between bitrates, but does not allow seeking.
Even Default renderer will operate without any Windows-related distortion, but at significant cost of volume.
For MPC-HC
its surprising that 'Internal Audio Renderer' reduces volume. 'Default' renderer performs as expected - introduced distortion when on maximum volume, but its easy to be fixed, the only downside is it operates in Shared mode, which is not optimal for playing DVD/BDs with 48KHz sample rate.
'MBSE Multichannel ASIO Renderer' acts as in Exclusive mode, does not reduce volume at all, even when it looks to introduce slight distortion around -100dB - nothing i should be able to hear with my setup.
Conclusion:
Foobar2000 'Default' renderer and MPC-HC 'Internal renderer' took away quite a lot of the volume, meaning you might need to increase the volume elsewhere.
Its actually surprising that there is any difference between different audio renderers. Even when there is little difference in terms of distortion, its actually quite interesting to see such different volume levels, as some renderers may take away 5 or 10dB of the dynamic range.