Equalizer APO & WASAPI

[highpurityusbcable]

For quite some time I was under the impression that EqApo just doesn't work on my computer but it actually just doesn't work with WASAPI. After some searching I found a post where user explains that APO is using it's own sound processing which isn't affected by DirectSound. But after trying a new APO install I can only see Windows mixer samplerate on my D10s display. Usually I use "WASAPI event" mode in foobar2000 and "WASAPI exclusive" when I watch videos in mpv or mpc. In these cases samplerate is always showing correctly. I want to understand why do such big databases of presets for APO exist if it doesn't even support "bit-perfect" mode to bypass Windows mixer. Or maybe I am completely wrong and it actually does bypass it, just showing wrong numbers on display. Or maybe I was fooling myself for a long time, thinking that WASAPI is "cleaner" and DirectSound is the same? I can definitely live without a system wide equalizer, just using parametric eq in foobar2000 but it would also be convenient to maintain one preset for all cases.
Sorry if this post is a mess but if you've read it and have time to give an elaborate answer, please do.

 

[andreasmaaan]

There was a long thread delving into these questions just a couple of days ago. Search “windows bit perfect” or similar.

The short answer though is that EQ APO does not bypass the Windows mixer but that this may not necessarily degrade performance in a way that is significant/audible.

 

[highpurityusbcable]

Thank you. Somehow missed that thread but it has all the answers. I've read it and there are only two choices: either to use APO or WASAPI exclusive modes. For peace of mind I will continue to use exclusive modes in my media players.

 

[daftcombo]

If you use Foobar2000 for instance, you can use the plug-in Convolver to apply EQ while using WASAPI (or ASIO).
For all the other sound of the PC (web browser, etc.) EqualizerAPO will do the EQ.

 

[highpurityusbcable]

If you use Foobar2000 for instance, you can use the plug-in Convolver to apply EQ while using WASAPI (or ASIO).
For all the other sound of the PC (web browser, etc.) EqualizerAPO will do the EQ.

Understood. In fact, the only case where I need a system wide eq is when watching live performances (only those that have flac audio tracks of course). Lives can sound a bit intense with my headphone default sound signature. Since there are no equalizers in mpv or mpc I wanted to use APO for this.

 

[escape2]

If you use Foobar2000 for instance, you can use the plug-in Convolver to apply EQ while using WASAPI (or ASIO).
For all the other sound of the PC (web browser, etc.) EqualizerAPO will do the EQ.

That's kind of what I settled on, too. With Foobar2000, I use MathAudio Room EQ plug-in because it does work in ASIO mode. For all other sound sources I use Eq APO.

 

[DDF]

Set the sub system to 24 bits, match sample rate of file with windows sample rate and playback is flawless with EAPO. I ran loopback distortion measures D/A/D through my codec with EAPO enabled executing my room eq and there was no difference compared to EAPO disabled

 

[AnalogSteph]

If you can keep digital levels just a hair below 0 dBFS and adjust sound device sample rate manually as needed, there should not be any loss in quality when using shared mode (BTW - there is a WASAPI shared mode addon for Foobar2000 as well, which comes standard with 1.6). There is a hard-limiter at an amplitude of 0.985 and that's about it.

The obsession with bit-perfect audio still stems from the pre-Vista days, it is not actually truly required unless you are using DSD over PCM and other "repackaged" digital data streams (AC-3, DTS).

With my old Asus Xonar D1 I am pretty much stuck in shared mode (long story - newer drivers won't init the card properly, the ASIO driver in the older ones is allergic to CPU load, and WASAPI exclusive is not implemented properly). It's a nuisance but quite manageable if you have software that lets you manage presets for hardware and Windows sample rate settings (yes, both, these are similar to other older designs like X-Fis with an independent hardware clock).

 

[escape2]

(BTW - there is a WASAPI shared mode addon for Foobar2000 as well, which comes standard with 1.6).

I'm running Foobar2000 v1.6.2, and the only WASAPI options I am seeing are "WASAPI (event)" and "WASAPI (push)." Neither one of them works in shared mode like ASIO does.

 

[highpurityusbcable]

It would be too much work to manually set samplerates. I have different files with different bitdepth and samplerates. Maybe in the end I will sacrifice exclusive mode for video players but I'll have to compare the sound quality with default renderer and WASAPI in mpv. Doubt I will hear any difference but this self-hypnosis is annoying.
And thank you for the replies.

 

[AnalogSteph]

I'm running Foobar2000 v1.6.2, and the only WASAPI options I am seeing are "WASAPI (event)" and "WASAPI (push)." Neither one of them works in shared mode like ASIO does.

Huh.
http://www.foobar2000.org/changelog

1.6

• Changed system requirements: Windows 7 and a processor with SSE2 instruction set. Windows XP is no longer supported.
• Default output mode is now WASAPI shared.

Anyway, here's the component:
https://www.foobar2000.org/components/view/foo_out_wasapis

It would be too much work to manually set samplerates. I have different files with different bitdepth and samplerates.

This is why I am using the SoX resampler DSP component for a standard output sample rate. I have almost all CD material, plus YouTube, so 44.1 it is. The card then upsamples that to 96 kHz internally, which it does at better quality than the Windows sound stack resampler (which, however, still is perfectly fine for less critical applications). I was using plain 44.1 for a long time but the hardware is just a bit happier at multiples of 48 kHz.

You never have to match output bit depth to anything, just use the largest your hardware will support.

 

[escape2]

Huh.
http://www.foobar2000.org/changelog

Anyway, here's the component:
https://www.foobar2000.org/components/view/foo_out_wasapis

Thanks. Installing the component manually made the "WASAPI (shared)" option show up.

 

[highpurityusbcable]

@AnalogSteph is this some kind of alternative to wasapi shared? Can you please describe what's the point of this component in very simple words. Thank you.
@escape2 Some new features of foobar2000 that appeared after 1.6 only become avaliable after a clean installation. I was also updating regularly and didn't see these options but then did a clean install. In a new foobar version "Default" sound output is wasapi shared.

 

[Vasr]

It would be too much work to manually set samplerates. I have different files with different bitdepth and samplerates. Maybe in the end I will sacrifice exclusive mode for video players but I'll have to compare the sound quality with default renderer and WASAPI in mpv. Doubt I will hear any difference but this self-hypnosis is annoying.
And thank you for the replies.

The sound improvement using eq filters when room modes are present far outweigh any audible artifacts of "bit-imperfection" through the chain required to accommodate it. Less so in headphones.

If you don't notice an obvious difference using EQ filters, then you don't need it for your application.

It is that simple.

Informative displays on DACs are potentially harmful to OCD sufferers.

 

[AnalogSteph]

@AnalogSteph is this some kind of alternative to wasapi shared?

Which one, foo_out_wasapis? No, this is the WASAPI (shared mode) output component.

 

[escape2]

Informative displays on DACs are potentially harmful to OCD sufferers.

 

[highpurityusbcable]

Which one, foo_out_wasapis? No, this is the WASAPI (shared mode) output component.

No, I mean sox resampler. It upscales audio files? I am not sure if it's really needed. If I understand what it really does of course.

@Vasr , yes, I don't need a display on a DAC but still D10s is everything I could ever need in terms of sound quality and simplicity of usage.

 

[FrantzM]

Question to those who know? What do we actually lose in bit-imperfect reproduction in term of dB or Fr or Timing or ?? What do we lose when reproduction is not bit-perfect ?

 

[highpurityusbcable]

I tried to compare so many times with my foobar2000 global keyboard shortcuts (alt+e for wasapi event and alt+s for shared). I was playing Hi-Res™ song and pressing these hotkeys, trying to hear any difference but honestly I didn't hear any. This is such a dumb feeling when you think that you lose some imaginary details because it's not "bit-perfect",

 

[daftcombo]

It would be too much work to manually set samplerates. I have different files with different bitdepth and samplerates. Maybe in the end I will sacrifice exclusive mode for video players but I'll have to compare the sound quality with default renderer and WASAPI in mpv. Doubt I will hear any difference but this self-hypnosis is annoying.
And thank you for the replies.

In Foobar you can use the plug-in SoX resampler just before Convolver in order to always send the same sample rate to Convolver. 44.1 kHz is good enough.