Ending the Windows Audio Quality Debate

[edechamps]

Is the limiter also bypassed on the input channels in this way?

I doubt there's any limiter on the input - that wouldn't make sense because the input can't reasonably be expected to exceed 0 dBFS (contrary to the mixer output). I haven't really checked though.

In any case, when I tested my "hack" to remove the limiter I made my measurement using a Virtual Audio Cable loopback, which means my observation applies to both output and input.

 

[Davide]

In any case, when I tested my "hack" to remove the limiter I made my measurement using a Virtual Audio Cable loopback, which means my observation applies to both output and input.

Ok, thank you!

 

[BeerBear]

if you want bit-perfect operation, the stream from the application has to match this format as well.

Just to clarify: it has to match the sample rate. But Windows' bit depth can be different, as long as it's at least 24bit and the audio content doesn't exceed that.
So you can play a 16bit file in a player that puts out a 32bit float stream into a 24bit driver and it's still bit-perfect (with the usual caveat of not triggering the limiter).

 

[daftcombo]

Filter Induced Digital Peaking
Perhaps less well known is that high pass filtering can also cause digital clipping, even if the filter only adds loss. How can this happen? The filter changes phase response which can then change how the different frequencies constructively add in the audio envelope. A good illustration of this is here.

This is a digital problem, not a Windows problem. Thankfully, the same solution used to avoid intersample overs, 4 dB digital preamp loss, should provide enough margin for this in practice as well.

That problem should not occur with linear-phase filters (like those you can create in Rephase), right?

 

[eddy555]

• Turn off Windows system sounds and enhancements --when you do that eapo says it is no longer installed for the device selected.

 

[daftcombo]

B

• Turn off Windows system sounds and enhancements --when you do that eapo says it is no longer installed for the device selected.

Because EQAPO is an enhancement.

 

[ichliebes]

Thank you a lot for your informative article!

I have a question (it may sound stupid...)

I'm using Windows 10 21H2, with EQAPO and Peace UI, through my JDS Labs Element III to my headphone. I just checked my setting (sound - playback - JDS - properties), the first thing I noticed is, the enhancement table is missing. However I found it under "advanced". But as I turned it off, the EQ was also gone. I then opened the configurator of EQAPO, and I noticed the "Use Original APO" checkbox is gray and I can't do anything (it's not selected though). I'm wondering what caused this to happen? I'm using an XPS Laptop from Dell, could it be the problem with Waves MaxxAudioPro thing?

 

[Jimbob54]

Thank you a lot for your informative article!

I have a question (it may sound stupid...)

I'm using Windows 10 21H2, with EQAPO and Peace UI, through my JDS Labs Element III to my headphone. I just checked my setting (sound - playback - JDS - properties), the first thing I noticed is, the enhancement table is missing. However I found it under "advanced". But as I turned it off, the EQ was also gone. I then opened the configurator of EQAPO, and I noticed the "Use Original APO" checkbox is gray and I can't do anything (it's not selected though). I'm wondering what caused this to happen? I'm using an XPS Laptop from Dell, could it be the problem with Waves MaxxAudioPro thing?

Turn back on enhancements within advanced. Eapo is such an enhancement. Don't worry if you don't have the enhancements tab. You may then have to apply eapo to the device again.

 

[Propheticus]

The answer is right above your post. APOs are enhancements, so to use Equalizer APO you should not turn them off.

 

[Jimbob54]

The answer is right above your post. APOs are enhancements, so to use Equalizer APO you should not turn them off.

To be fair, its a little daft having said enhancements but also other enhancements in another tab that can be disabled. Not massively intuitive.

 

[Propheticus]

It's also not intuitive the opening post first talks about installing EQAPO and deselecting "use original APO" which removes the enhancements tab and then summarises "Turn off Windows system sounds and enhancements". This leads people to look for something called enhancements, which they find under the advanced tab.

 

[Jimbob54]

It's also not intuitive the opening post first talks about installing EQAPO and deselecting "use original APO" which removes the enhancements tab and then summarises "Turn off Windows system sounds and enhancements". This leads people to look for something called enhancements, which they find under the advanced tab.

Welcome to the Wonderful World of Windows settings!

 

[Katji]

I left it at the default/s
and EAPO does work.

i can't check now because the device is not connected, but...

Equalizer APO / Documentation Wiki / Documentation

sourceforge.net

Scroll down to

Configurator​

By default, Equalizer APO will try to keep the functionality of other APOs that have been shipped with the sound card driver ("original APOs"). In some cases, this causes instabilities in the audio processing. The Configurator offers troubleshooting options to adjust how the original APOs are used.

If you experience instabilities during playback or recording when using Equalizer APO, you can try to disable the usage of the original APOs in the Configurator:
1. Select your audio device by clicking on its connection name.
2. Enable the troubleshooting options.
3. Uncheck both "Use original APO" checkboxes.

<image>

Control Panel​

If you installed Equalizer APO and no changes to the configuration file lead to any changes in the signal, APOs might have been disabled for the device in the Control Panel.

[...etc.]

 

[Katji]

Welcome to the Wonderful World of Windows settings!

...I'd be pleased to know if any particular Linux GUI does it better. Like more coherently structured. Or there is nothing but the config files, finding out which and where they are.
Because I think I'll have to go there eventually / part ways with Microsoft.
(I've only used unix, with no X-Windows.)

 

[Presently42]

The answer is right above your post. APOs are enhancements, so to use Equalizer APO you should not turn them off.

This is not strictly correct: on my system, enabling effects worsens the noise floor by a huge amount; whereas not disabling doesn't impede equaliser apo from working. I've told the devs of this, but they've not yet implemented anything to counter the popup, asking for enhancements to be enabled. I'm currently working on a tutorial, with measurements, that should clarify these results. For now, see my own thread on the topic

 

[Propheticus]

Your post shows the exact confusion discussed above... The (allowing of signal processing) enhancements option you should not turn off are on the advanced tab.
The disable all sound effects just turns off all the drivers effects offered on that enhancements tab (which should be gone anyway if you do not keep original APOs during install)
This alone does not disable the audio device from running other enhancements (like EAPO) outside the device driver ones.

 

[Katji]

bingo!
...Maybe that should be bold/emphasis. .....

Another point of confusion that i bumped into before and troubled me again today is people being told they cannot use EAPO with ASIO.
Maybe so, strictly speaking, but it's not good.
Thing is, the ASIO device drivers, typically/generally XMOS/Thesycon are billed as ASIO and they present as ASIO.
So on the face of it, there is ASIO and there is EAPO, working, and no WASAPI or whatever in sight.

 

[dasdoing]

there were conflicting enhancement settings in W11, that seams to be gone now with latest updates. you had one in the regular setting, and one in the control panel. now I only see it in control panel. that made EQ-APO confusing to setup in the past.

 

[Offler]

I would like to put info about this software - LatencyMon:

Resplendence Software - LatencyMon: suitability checker for real-time audio and other tasks

LatencyMon: suitability checker for real-time audio and other tasks

www.resplendence.com

Even PC gaming has its snake-oil and one of them is called 'Input Lag'. A lot of sellers claim that certain hardware will eliminate input lag present in your system. In most cases input lag is caused by garbage in your OS, rather than hardware, but a lot of gamers did have fallen for it getting expensive mice and keyboards.

However, 'Input lag' is much more a problem for audio/video conferencing than for mouse/keyboard input, and this is why was this tool originally designed for.

I found it very useful for testing my IOs and IRQs, diagnosing performance of drivers and hardware. This was over year ago:

This is after series of optimizations:

Both tests were done when system was idle, and for duration of 1 minute.

Audio-related benefits of such tuning:
- You may notice that HDAudioBus.sys is not present in first screen - its because the driver turns off in that scenario for power saving reasons. In such scenario you may hear "pop" sound everytime system plays a sound. Solution was to install a different driver - there might be another solution available by editing registry.

General idea
There is small chance that any driver will not be operating consistently, and there will be small drop outs. This may be perceived as a stuttering of image or sound. With this tool you may found the source in case if its hardware of driver related.

On my specific system I found out that USB was sending data to threads 0, 3 and 15 while the amount of ISR/DPC calls was quite high. I found out that when i force USB controller on Thread 15, amount of calls reduces to 1/10 and highest execution decreases as well. It means that the driver was routing data through 3 threads, while one of those was "closest" or "preferred" for the USB and data will be processed in less complicated manner. It wont make my mouse to have lower perceivable input lag, but its important of USB devices (such as optical drive, or soundcard).

I used the tool to replace several drivers, for checking if registry entries actually did something, and whether if different PCI-E or onboard devices operate well, and if there is any way to improve it.

 

[anphex]

Is there something about going the other way? Namely downsampling when I play a movie with 48 Khz and my Windows is set to 44,1 Khz. Since Windows "upsampling" is just repeat bit it seems, is downsampling just dropping bits?