I have a laptop Acer Predator G9-792
It has 2 or 4 speakers (there is 5 holes but not sure are all holes have speaker inside) and subwoofer
On windows 10 everything working as expected, but in Ubuntu 16.10 only subwoofer being used to output sound
I've tried recommendations here – Enable Dolby 5.1 or at least subwoofer on Acer laptop?
including enabling 3,4,5,6 channels – sound either stop working or keep working through subfoower
alsamixer with extra driver support also didn't work
Is there anything I can try to enable normal sound on the laptop?
I just got the same machine yesterday. Here is what I did to get sound working.
Then using the HDAJackRetask select Realtex ALC255 codec and choose "Show unconnected pins" option. I put an override on the following items: 0x14 - change to Internal Speaker (LFE) 0x17 - change to Internal Speaker 0x1b - change to Internal Speaker (Back)
I played around for a long time with various advanced overrides but could never get it quite perfect, however using these options you at least get good sound on left and right speakers. I don't think it is playing through the front speakers, there are 2 speakers on the bottom front and I believe it is using both of these now. I'm happy with it for now, I mainly use headphones anyway. I should add, I did this on Ubuntu 16.04 and later on Xubuntu 17.04. I was able to get sound working well on both.
On Ubuntu 16.04 I also had to add an override for headphones on 0x21 changing the channel to 2 in advanced options. In Xubuntu I didn't have to do that. This could have been due to playing around with all of the other pins first until I figured out which ones were actually tied to speakers.
I'm hoping an updated firmware or kernel will provide a better fix in the near future.
---Update--- I just installed Xubuntu 19. Not sure if this was an issue 2 years ago, but I cannot get it to apply so I the only way to test is to make the changes above and click Install boot override then reboot and test.
---Update--- Same with Xubuntu 20.04. Same pins above fixed the sound and it has to be applied as a boot override.