...

...

No change.

http://www.alsa-project.org/db/?f=30b3f0087374b914a20dbe20a618fb892a5d6fd5

...

Are there any offical specificaion ?

So far most review only mention stereo speakers and subwoofer, the

service

...

guide only show how to replace two internal speakers

Service manual mentions "Dolby®-certified surround sound system with two built-in stereo

speakers and

one subwoofer supporting low-frequency effects"

so all additional channels what I'm hearing in Windows is emulated. I hope that it is clear now that my laptop has two internal speakers and one subwoofer.

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pc...

You need to define your 2.1 chmap if the subwoofer only use left channel

Compiling and running PulseAudio from git

http://colin.guthr.ie/2010/09/compiling-and-running-pulseaudio-from-git/