Comment 13 for bug 728161

I have meanwhile also found a workaround for ubuntu 11.04

1. installed linux-alsa-driver from repository ppa:ubuntu-audio-dev/ppa
see http://ppa.launchpad.net/ubuntu-audio-dev/ppa/ubuntu/pool/main/l/linux-alsa-driver-modules-2.6.38/

sudo add-apt-repository ppa:ubuntu-audio-dev/ppa
sudo apt-get update
sudo apt-get install linux-alsa-driver-modules-$(uname -r)

note:
at the moment there are only packages for kernel 2.6.38-8 available

2. opened file /etc/pulse/daemon.conf and replaced

a) entry

; enable-lfe-remixing = no

with

enable-lfe-remixing = yes

and
b) entry

; default-sample-channels = 2

with

default-sample-channels = 6

3. opened file /etc/modprobe.d/alsa-base.conf and added

options snd-hda-intel model=basic

at the end of this file

4. opened file /etc/modules and added

snd-hda-intel model=basic

at the end of this file

5. Then I rebooted laptop.

Subwoofer is now working unter ubuntu 11.04 (with same rich, full sound as under Windows).