Is there some hidden volume attenuation in Windows when selecting 5.1/7.1 audio?

[Tre2023]

Idk why but when selecting 5.1/7.1 audio in windows the volume sounds noticeably lower even when im playing back the same stereo source file, i don't have any speaker fill, or upmixing or anyting related to that enabled and i've noticed it across multiple equipment like AVR, and soundbars.

I have noticed similar behavior in my Mac mini M1. The output level is just slightly lower using the 5.1/7.1 output setting when playing back 2.0 signals vs the 2.0 output setting.

 

[Chrispy]

I'm using the auto format decoding so most likely it just accepts whatever configuration is sent and does nothing more, etc windows most likely just mutes or sends silence to unused channels.

Update: yeah with AFD it just reports exactly the configuration you send it.

Been a while since I've used my Sony avr, but AFD sounds like the direct mode, but what are those particular codecs it receives, and do they differ between 2ch and 5.1 or 7.1? Not familiar much with using windows for sound, tho I've had multich pcm do some funky things with some gear, tho.

 

[Yviena]

Been a while since I've used my Sony avr, but AFD sounds like the direct mode, but what are those particular codecs it receives, and do they differ between 2ch and 5.1 or 7.1? Not familiar much with using windows for sound, tho I've had multich pcm do some funky things with some gear, tho.

They all display as LPCM (channel count same as configured in windows)

 

[popej]

Regardless of the reason, it is quite nice outcom. Usually stereo recordings suffer from loudness war, while multichannel recordings has lower reference level. Attenuating volume for 2.0 evens out the volume levels a bit.

 

[xanalog]

Idk why but when selecting 5.1/7.1 audio in windows the volume sounds noticeably lower even when im playing back the same stereo source file, i don't have any speaker fill, or upmixing or anyting related to that enabled and i've noticed it across multiple equipment like AVR, and soundbars.

I think this may be my first time recommending the use of a chatBot.
I even tried a few questions about your question, and it provided some very explorable ideas, if not downright the correct one.

I find chatBots do a pretty good job w/Windows11 assistance. Surely much better than trying to find an answer -a needle in a haystack- at support.microsoft.com
But you have to pay attention to how you formulate the question(s) as an iterative process and confirm results provided!

You could pretend you are advancing your skills at vibe-coding...

 

[Tre2023]

They all display as LPCM (channel count same as configured in windows)

Even with the 5.1/7.1 setting, audio output is louder than when the Apple TV or Apple Music apps are set to bitstream Dolby signals. But, I do switch back and forth and leave it at 2.0 setting for two channel music.

What is also interesting is when it is set to 5.1/7.1 LCPM output, up mixing the two channel signal leaves vocals in the Fronts speakers instead of forcing it to the Center Channel speaker when set to 2.0.