what the hell is going on

this is the difference:

 

Impressive, the yellow one is loosing all the low end while being louder (+3db) when at 100hz and up ... crazy

Remember it is recorded at line-out using the exact same audio chip. The only difference is the driver used for playback ...
There is something really strange happening here.

 

Holy crap I found it !
In the bios there is a setting for the audio chip to configure which type of hardware is used : it was defined as "multimedia", I switched to "hifi" and now the sound is the exact same with both manufacturer driver and ASIO ...

Funny to see that ASIO4ALL seems to "bypass" those BIOS setting btw ...

 

'A Windows Server system in core mode, fully optimized with the AudiophileOptimizer, runs only 5 to 7 services and about 15 to 20
processes. Almost 150 unnecessary drivers and services are disabled, resulting in the optimal platform for ultra high-end audio reproduction.'
https://www.highend-audiopc.com/audiophile-optimizer
'Improve audio performance by giving audio task more priority, improve low latency stability, and increase accuracy of clock resolution.
Isolate non-audio processes and reduce its priority to minimize any possible interference to audio task and related processes.
Stop/Disable most non-audio system services greatly reducing system footprints for pure audio performance.'
https://www.fidelizer-audio.com/

Reduced processes on my system:
https://ibb.co/55b7BFD
No of services = 35.
Background processes = 9.
Check No of yours.

 

Last edited: Feb 8, 2023

Off topic, but thanks for the info.
BTW I noticed that one of the biggest PC audio problem is not even mentioned on the website : DPC latency ...

 

Just wanted to illustrate the impact of CPU stress on sound quality. The stress caused by sound output drivers which are using more processing layers [or just more processing power in general] than the others is one thing that sets them apart in respect to sound quality. So even a new revision of the same driver can sound different (better) if better programmed.
DPC latency is the next of kin but not related to output drivers in general.