Currently have an Asus N56DP. Using an older answer I could get the subwoofer to work under 12.04 but after an upgrade to 12.10 that method stopped working.
lspci|grep -i audio
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Trinity HDMI Audio Controller
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller (rev 01)
lsusb
Bus 002 Device 002: ID 1bcf:2883 Sunplus Innovation Technology Inc.
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
A bit more info. the fix for the n56v series worked under ubuntu 12.04 to get the subwoofer working but was a bit wonky. The fix was the one that added these lines to /etc/rc.local:
echo 0x1e 0x99130112 > /sys/class/sound/hwC0D0/user_pin_configs
echo 1 > /sys/class/sound/hwC0D0/reconfig
and added this line to /etc/modprobe.d/alsa-base.conf:
options snd-hda-intel model=asus-mode4
lastly, my 13.10 was arrived at by upgrading from 12.04 through each version to 13.10.