I have read that there's a problem to get the subwoofer working in these laptops. I tried this solution No sound from external subwoofer but I don't how to prove that the subwoofer is properly functioning. I use Pulseaudio equalizer and the bass sound seems to work fine, but when I go to the Sound Settings, I can't move the bar where it says 'Subwoofer' in my sound card option, so I don't know if everything is alright. If someone has a solution I would like to know, because there isn't much information regarding this. By the way, I'm using Ubuntu 12.04 64 bits.
Thanks beforehand, Dave
EDIT ----------- Possible Solution
Well, I will post a solution that worked for me and I think it will help a lot of users. I finally got the subwoofer working.
Besides adding in
/etc/modprobe.d/alsa-base.conf the line
options snd-hda-intel model=asus-mode4
I deleted the lines with
load-module module-combine and
/etc/pulse/default.pa (in the home folder there's also a ~/.pulse/default.pa file, I don't know if it has the lines too). Or just delete the ~/.pulse/default.pa file
To assure all the channels are working, I think this command tells me that
speaker-test -c6 -l1 -twav
I use pulseaudio-equalizer and the bass sounds very well when properly adjusted. Also, all the channels seems to work fine and the sound is even better than in Windows (where I don't have an equalizer).
I pointed out before a module-combine and module-combine-sink problem, because one day I turned on my laptop and pulseaudio didn't work. So I deleted the lines with that names (don't know if they came by default, maybe I added them sometime when I was trying to fix my speakers).
One important thing is to add, when using the equalizer, in
~/.pulse/default.pa the command
load-module module-combine channels=6 channel_map=front-left,front-right,rear-left,rear-right,front-center,lfe
After all this, I can now move the Subwoofer bar in the Sound configuration. Anyways, the Equalizer does a great job and it improves the sound a lot.