Ending the Windows Audio Quality Debate

[Offler]

Check the block diagram of some Realtek chips and notice that volume controls are done after DAC, and therefore analog. No hardware volume control on SPDIF though.
View attachment 178428

This is almost identical to diagram of alc1200 i found some months ago, however i did not found any diagram for ALC1220.

SPDIF acts just as a passthrough and every modification to audio has to be done on software level. Driver keeps buffer ready for 32bit INT PCM data all the time for no apparent reason. So when I play bluray audio (usually 48KHz 24bit) in Exclusive mode, it will first convert 24bit INT to 24bit (Padded) where are added 8 empty bits and only then its transferred out of SPDIF.

But since at least my onboard audio card has NE5532 for headphone output, it indicates there is at least some hw volume control circuitry.

Downside of SPDIF in this solution is that OS will lose volume control when Exclusive mode is engaged. Upside is that you can be absolutely sure that in exclusive mode was no APO active, and there was also no "hardware enhancement" of the output data before presented to external DAC.

Very old MediaPlayer Classic will also report if there was any software filter used in the processing of video, subtitle or audiostream and if set properly there is scenario when there is absolutely no processing used.

 

[dasdoing]

But you can't remove that -10 dB attenuation filter, because if you do, then as soon as you start playing high-volume/low-headroom content (say games, unnormalized music), it's going to clip like crazy.

but you are removing it the same way with the software volume. in both cases you will have to undo the extra gain after the movie.
I will just use the volume knob in VLC-Player which goes up to 125%. the peak-meter I mentioned before comes in handy when watching movies. My EQ-APO chain is actualy always in the red....I just make sure the peak-meter never shows me a full scale peak

 

[edechamps]

but you are removing it the same way with the software volume. in both cases you will have to undo the extra gain after the movie

Yes, but with software volume control, that happens transparently and automatically as you adjust the Windows master volume control setting. You don't need to go to Equalizer APO and mess with the filters. You just adjust the volume as usual and the system takes care of the rest. It's foolproof and it always adapts optimally to whatever content you're listening to. You don't even need to calculate the minimum attenuation required when setting up the EQ filters - you can literally just ignore the problem altogether.

I do agree with you though - the use case for something like WinSoftVol is very niche and specialized. I never claimed otherwise

I will just use the volume knob in VLC-Player which goes up to 125%

If you do this, do make sure that VLC is outputting floating-point (assuming it can do that - I don't use VLC) so that you can't clip in the integer domain between VLC and the Windows audio engine.

 

[Offler]

I'm using Windows 11, Tidal App and an iFi Zen DAC. Do you think EAPO could benefit the quality of my system in anyway? Thank you!

I assume that Windows 11 has still same issues related to CAudioLimiter as in the first post, so i assume the answer is yes for Shared mode.

 

[mga2009]

I've read all the thread, trying to get my head around the technical stuff, and I can't really say I've got it all, but thanks for the shared knowledge... and I will just keep reading trying to learn something else.

So... apart than using Windows's volume to full throttle and use EQ Apo with a -6db/-10db gain... Is there something else I can do to get proper audio without clipping it? Maybe use Linux? That would be a bummer as all my media comes from a Windows PC (movies, games, music, etc.).

Cheers

 

[Offler]

I've read all the thread, trying to get my head around the technical stuff, and I can't really say I've got it all, but thanks for the shared knowledge... and I will just keep reading trying to learn something else.

So... apart than using Windows's volume to full throttle and use EQ Apo with a -6db/-10db gain... Is there something else I can do to get proper audio without clipping it? Maybe use Linux? That would be a bummer as all my media comes from a Windows PC (movies, games, music, etc.).

Cheers

For gaming audio, that is basically it. For media and some streams you can switch some media players to WASAPI Exclusive mode, to bypass all Windows-related postprocessing alltogether.

 

[tjtremor]

-4db for pre-amp seems excessive to me for line-out, on the external AMP side it sound like I lost about -8db on the volume/amplification which is alot.

I'm using 1220-vb, I always have my output at 32bit 192khz so it might be using the ESS SABRE9118 DAC (also included on the board).

I honestly don't hear much difference from 0db and -4db on the pre-amp for sound clarity; using a vintage Onkyo with rp-600m Klipsch speakers, which have crazy clarity / stage imaging at low and high volume.

I left the pre-amp -2db; It might bring some extra clarity to very low sound(highs) but very doubtful unless you run crazy expensive speakers/amps.

I also don't see how windows clips peaks since most audio comes out around 50%, maybe some 70% peaks.

 

[dasdoing]

As showed here, the windows limiter is actualy a good thing to have https://www.audiosciencereview.com/...ftware-volume-control.5922/page-2#post-172865

 

[srrxr71]

So what’s the consensus? Do we have a best practices guide? Just -0.2dB on equalizer APO? Let Windows do everything else?

 

[dasdoing]

-0.2dB

I understand where this is coming from, but a transient hitting 0dBFS is not stopping there. you want to make sure to never hit the limiter, better use a full dB.

 

[srrxr71]

I understand where this is coming from, but a transient hitting 0dBFS is not stopping there. you want to make sure to never hit the limiter, better use a full dB.

Fair enough. Then that’s it? Nothing else to worry about?

 

[dasdoing]

Fair enough. Then that’s it? Nothing else to worry about?

you better wait until they come and disagree with me lol

personaly I prefer to have the limiter

 

[edechamps]

I mean, if you think about it, I don't think it's that clear cut that you should even "worry" about CAudioLimiter. For signal levels that close to 0dBFS, you'd be worried about intersample overs anyway, CAudioLimiter or not. In fact, one could perhaps argue that CAudioLimiter might make intersample overs less likely (I'm not claiming it does, but I guess it's plausible).

I'd be sceptical that anyone could ABX CAudioLimiter vs. "pure" in typical audio content. It's a very subtle, very limited (pun intended) effect.

And if by any chance you ever end up in cases where the floating point signal could exceed full scale (for whatever reason - granted that's not supposed to happen in a standard playback scenario) then you really, really want CAudioLimiter to be there as it is incredibly effective at keeping the nasty clipping harmonics away from your ears. Presumably that's what it's designed to do.

But anyway… if you really want to defeat CAudioLimiter, you can either use any APO bypass sound path (WASAPI Exclusive, KS, native ASIO), or you can insert a ~1 dB attenuation in Equalizer APO, or simply reduce the volume by ~1 dB in your music player (and if it doesn't have software volume control, you can always use the Windows per-application mixer volume controls for that). But again, the -1 dB attenuation is something that would be advised even without CAudioLimiter in the picture, just to prevent intersample overs.

 

[srrxr71]

you better wait until they come and disagree with me lol

personaly I prefer to have the limiter

So you mean basically “do nothing”?

 

[dasdoing]

So you mean basically “do nothing”?

yes I do. Ede explained it perfectly in his post above

 

[flaviowolff]

Why is it recommended to turn off audio enhancements

Summary Recommendations:

• Install Equalizer APO and use it to disable original APOs and set EAPO's preamp gain at ~ -4 dB to avoid upsample overs, filtering induced peaks, and the Windows CAudioLimiter
• Set Windows audio to 24 bits so that it's added dither doesn't compromise dynamic range
• Set Windows sample rate to the same rate as the native file, or to 96 kHz if you play back high resolution material
• Turn off Windows system sounds and enhancements
• Install "remote desktop" for "Spotify Connect"-like added convenience, for all your digital sources
• Take the money saved and buy more music, better speakers and a few bottles of wine

Both options in bold are mutually exclusive here. If I disable enhancements (via enhancements tab), EQapo wont work and will ask me to re-enable it whenever I open it's editor app.

 

[storing]

Yeah that doesn't look completely right, EqAPO as far as I'm aware takes care of all of that (EqAPO is in fact one of those 'enhancements'), no need for that second step.

 

[Offler]

Summary Recommendations:

• Install Equalizer APO and use it to disable original APOs and set EAPO's preamp gain at ~ -4 dB to avoid upsample overs, filtering induced peaks, and the Windows CAudioLimiter
• Set Windows audio to 24 bits so that it's added dither doesn't compromise dynamic range
• Set Windows sample rate to the same rate as the native file, or to 96 kHz if you play back high resolution material
• Turn off Windows system sounds and enhancements
• Install "remote desktop" for "Spotify Connect"-like added convenience, for all your digital sources
• Take the money saved and buy more music, better speakers and a few bottles of wine

After few months of intensive testing and measuring I would suggest following updates:

• Install Equalizer APO and use it to disable original APOs and set EAPO's preamp gain at -6.2 dB to avoid upsample overs, filtering induced peaks, and the Windows CAudioLimiter
• Set Windows audio to 24 bits so that it's added dither doesn't compromise dynamic range
• Set Windows sample rate to the same rate as the native file, or to 192 kHz if you play unknown audio format
• Have a media player capable of using WASAPI: Exclusive mode and use it for 'critical listening'
• Turn off Windows system sounds and enhancements
• Install "remote desktop" for "Spotify Connect"-like added convenience, for all your digital sources
• Take the money saved and buy more music, better speakers and a few bottles of wine

Notes:
On -6.2 dB
a) at -0.14dB CAudioLimiter will stop making trouble for single source. THD improved from -60 to -80dB.
b) at ~ -4dB risk of triggerring CAudioLimiter was much reduced when mixing more sources.
c) at -6,2dB risk of triggerring CAudioLimiter when mixing two sources was reduced to zero. It also negates IMD as a result of mixing.
d) If you use Equalizer for improving sound, -6.2dB has to be on 'Peak Gain' on 'Estimated properties' tab.


On 192kHz
a) If the source is unknown, or only WASAPI Shared mode is available or there is another reason that you cannot avoid re-sampling, 192kHz mode will create least artifacts, but all of them above threshold of 20kHz.
b) Unfortunately its not always possible to know which audio is used in computer game or in stream.

IMD measurings for 96kHz and 192kHz output with 44.1kHz source tone sines at 18 and 19kHz:

Disclaimer: My measuring equipment is not good, nor accurate, but the results under controlled conditions were repeatable and constant. If someone would verify this, it would be great.


Media Players with WASAPI: Exclusive
a) This mode bypass ALL Windows filters and audio is sent to speakers "As is"
No mixing, no resampling, no limiter, absolutely no software filter in Windows is used.
b) Media files are rendered in their native sample and bitrate
c) There is little to no difference between WASAPI: Exclusive and ASIO modes.
d) It will mute all other audio sources in Windows.

And very last note... If you want less technical and more subjective way to tell how Windows does sound, simply compare music in Shared and Exclusive mode.

 

[edechamps]

Set Windows audio to 24 bits so that it's added dither doesn't compromise dynamic range
c) at -6,2dB risk of triggerring CAudioLimiter when mixing two sources was reduced to zero. It also negates IMD as a result of mixing.

So you care about extracting every little bit of dynamic range, yet you recommend a -6 dB attenuation (which is quite substantial) just on the off chance that mixed audio might clip? Does audio quality really matter that much when multiple applications are playing audio at the same time, anyway?

 

[Offler]

So you care about extracting every little bit of dynamic range, yet you recommend a -6 dB attenuation (which is quite substantial) just on the off chance that mixed audio might clip? Does audio quality really matter that much when multiple applications are playing audio at the same time, anyway?

The effects of triggering CAudioLimiter are significant increase of IMD and THD, while still in the digital domain.

This screen shows IMD when CAudioLimiter is triggered by dual sine at 50Hz and 7kHz:

And this is when there is attenuation applied either in signal or EAPO:

I would rather have an anti-clipping solution for mixing other than CAudioLimiter - one which does not introduce distortion at all.

The volume attenuation can be at least compensated by amplifier outside digital domain. Distortion however cannot.