Ending the Windows Audio Quality Debate

[MaxwellsEq]

If you are interested, their manual is really well done and contains a lot of neat background info

The manual is superb and covers the complexity of the device. Every time I pick it up I spot something I missed in the past.

 

[Sernyl]

Sorry to be so late :
Is EAPO usefull with the "Realtek optical output" ALC1220 chip I have on my MB ?
BTW it does not seem to be worse than an external Xmos USB to optical box.
Thanks by advance,

 

[MaxwellsEq]

Sorry to be so late :
Is EAPO usefull with the "Realtek optical output" ALC1220 chip I have on my MB ?
BTW it does not seem to be worse than an external Xmos USB to optical box.
Thanks by advance,

It doesn't have anything to do with chipsets or connections. It allows Windows to support PEQ, and as a side-effect can override some nasty Windows behaviours.

 

[Sernyl]

Thank you for the answer.
English is not my native language.
I mentionned the chipset just in case.
If I understand correctly, you mean that an optical audio output is, like the analog one, affected by "some nasty Windows behaviours" ?
Regards,

 

[MaxwellsEq]

Thank you for the answer.
English is not my native language.
I mentionned the chipset just in case.
If I understand correctly, you mean that an optical audio output is, like the analog one, affected by "some nasty Windows behaviours" ?
Regards,

Imagine you have a recording of Beetles"Help" stored on your PC's hard drive as help.flac. You want to listen to it.

You plug headphones into your PC and use a player like Foobar2000 to play it, but you don't want to use "Exclusive Mode" because you also want to use software to EQ it. Between the player and the headphones are a bunch of Windows functions (some are APOs). Some are native Windows, some come from drivers shipped with audio devices. You can't see them. Some degrade the sound a lot (e.g. by compression).

So you decide to buy a DAC and plug it into the USB port. BUT, these Windows APO functions sit between your player and the DAC plugged into your USB port.

So you decide to plug the DAC into the optical port. BUT, these Windows APO functions sit between your player and the DAC plugged into your optical port.

They are always there whether you use the onboard chipset, a USB connected device, an optical connection. You can bypass them by using Exclusive Mode on your player, but this can limit some control of some DACs and prevent you applying equalisation.

EAPO is another APO, that sits between your player and the onboard chipset, USB DAC or Optical DAC. It allows PEQ. It also has an option to DISABLE other APOs including the Windows limiter. This can have a very big benefit in sound quality.

 

[Sernyl]

They are always there whether you use the onboard chipset, a USB connected device, an optical connection. You can bypass them by using Exclusive Mode on your player, but this can limit some control of some DACs and prevent you applying equalisation.

EAPO is another APO, that sits between your player and the onboard chipset, USB DAC or Optical DAC. It allows PEQ. It also has an option to DISABLE other APOs including the Windows limiter. This can have a very big benefit in sound quality.

Thanks again for the explanation.
In my case, I'm already using Foobar and "Exclusive Mode" only, and downstream control is done with the ADI-2 pro.
Looks like I don't need EAPO in this configuration, right ?

 

[MaxwellsEq]

Thanks again for the explanation.
In my case, I'm already using Foobar and "Exclusive Mode" only, and downstream control is done with the ADI-2 pro.
Looks like I don't need EAPO in this configuration, right ?

That's correct. Using exclusive mode means EAPO would not be used. If you want to do EQ in Foobar2000, there is the MathAudio plug-in.

 

[Skydeaner]

I know this post is a couple of years old but I am extremely thankful for your time testing this. I registered just to say this and I've never been to these forums but it looks like it's gonna be a lot of fun. Anyways Thanks again @DDF for your hard work.

 

[Rednaxela]

Sorry if this has has been discussed already, but I ran into something that might be of interest here.

Context: applying an EQAPO filter set on the 3.5mm headphones out of my Windows 11 Acer laptop, to equalize a pair of IEMs.

Windows uses audio processing objects (APOs) to provide software based digital signal processing for it's audio streams. First Surprise: Some hidden non defeatable APO made a mess of it, even with "all effects off' in Windows. Naughty Windows! My music system and work PCs didn't show this issue, so it may be caused by an APO for the Dell Realtek soundcard. To verify the measurement, I retested with RMAA's spectrum analyzer and the tones at a lower level (to make sure it wasn't intermediate clipping or the CAudioLimiter). Same outcome.

To try and fix this, I then installed (free) Equalizer APO (EAPO). This brilliant software supports a trouble shooting mode that turns off all "original" (stock) system APOs:

On my laptop, this setting at 3) is grayed out.

It is also unchecked. So initally I thought all was good.


Thing is, EQAPO requires Audio enhancements to be switched on.

(Image taken from here for the English UI.)


However, switching between Device Default Effects and Off resulted in a very noticeable sound difference. Like operating a loudness button - really nothing subtle. As I had all EQAPO filters disengaged, and the EQAPO configuration settings were as outlined above, I did not expect to hear any sound change.


Turns out that the difference was caused by Acer TrueHarmony. I found it in the Realtek Audio Console.

Long story short, I now have this switched off as well, and hear no more difference between the two Windows Audio enhancements settings.


I am not sure what this all means. It appears that despite the findings shared by the OP there may still be things going on outside of what is covered by their recommendations in the first post. Sadly I don't have the gear (and frankly the skills) to establish for sure that I killed all additional processing. But hearing no differences between enhancements on and off does give me some peace of mind.

In any case I'm glad to eventually have found this TrueHarmony switch and hope this info is of help to some.