High distortion levels with Windows 10

[audio_tony]

I've recently switched from Windows 7 to Windows 10 for my audio test rig.

However I've been experiencing high levels of distortion at or close to 0dB as below, Windows is heavily distorted but using Linux the FFT is clean? Below 0dB (-1dB) is clean and doesn't suffer from this issue.

I'm not using ASIO, just the standard Windows drivers (which always worked fine in Windows 7).

Top FFT uses a Kaiser 7 window, bottom FFT uses a Blackman-Harris 7 window (changing window types in Windows makes no difference so it's not that).

Anyone have any idea what might be wrong?

Windows:

Linux:

 

[Keith_W]

Windows Mixer would be my guess. If you use WASAPI Shared, everything goes through the mixer. It resamples audio and does all sorts of unspeakable things to it without asking. It is optimised for speed and low CPU usage and not sound quality.

 

[staticV3]

It's a limiter built into Windows called CAudioLimiter

More details here:

Ending the Windows Audio Quality Debate

A debate has been long raging in the audio community that Windows isn't fit for use in a high resolution audio system. Sceptics counterargued that bits are bits and Windows audio degradations are a figment of an over-active audiophile imagination. I decided to investigate this as I kept...

www.audiosciencereview.com

 

[Sokel]

Standard windows drivers at what mode though?
Using the plain shared output is a no,use WASAPI exclusive or ASIO.

 

[staticV3]

Windows Mixer would be my guess. If you use WASAPI Shared, everything goes through the mixer. It resamples audio and does all sorts of unspeakable things to it without asking. It is optimised for speed and low CPU usage and not sound quality.

IME doing Null tests with Wasapi Loopback, Windows' mixer has basically flawless sound quality, with the exception of CAudioLimiter.

 

[audio_tony]

Thanks everyone, I'll take a look at the post linked by @staticV3

Surprisingly, despite working in IT (server / networking) for many years, I profess to know very little about Windows audio. It's always just worked for me on Windows 7 and 8.

I only switched from Windows 7 as I was unable to find a Win 7 driver for my SMSL PO100AK which I have started using as my signal source.

 

[Sokel]

That's at -2dB at all modes:



ASIO



WASAPI exclusive



Direct sound (shared)



..and all together for easy view:



No difference if you set it right.

Edit:By the way,Multitone Analyzer is the only app one can mix modes this way,from the ones I have tested so far (maybe payed REW can do it too,never tried it)

 

[audio_tony]

Well I 'fixed' it. After much messing around with equaliser APO etc., I installed Linux and Wine.

I now have lovely clean waveforms, even at 0dB, and I can run most of the Windows apps I use primarily - sadly I can't get Virtin's MI to run under Wine though.

I can also run REW natively on Linux of course.

 

[AnalogSteph]

I can also run REW natively on Linux of course.

Although that wouldn't have been a problem on Windows either given that the 64-bit version of REW supports WASAPI exclusive mode I/O and ASIO.

 

[audio_tony]

Although that wouldn't have been a problem on Windows either given that the 64-bit version of REW supports WASAPI exclusive mode I/O and ASIO.

True, but I tend to prefer WaveSpectra, Arta and Virtins Mi (which I have a licence for).

I will persevere at getting Virtins to work - I'm aware older versions work, but I seem to recall the newer versions attempt to install USB drivers for their various products, and this is where things go wrong.

I can always run Windows 7 in VirtualBox if needs be.

Windows 10 has proven to be a frustrating experience for me (in audio terms). Even more frustrating is that the past few times it's updated, it's added apps back that I previously removed, and tried to get me to sign in with a Hotmail account. No thanks.

 

[audio_tony]

As a little experiment today, I restored a 2012 Server installation I was using a few years ago - it doesn't have this issue and works perfectly at 0dB....

It's also notably faster than Windows 10...

I doubt I'll be able to get Windows 8 (Server 2012) drivers for my SMSL PRO100AK though...!