marc@XPS:~$ lspci -knn -s 00:1b
00:1b.0 Audio device [0403]: Intel Corporation 82801H (ICH8 Family) HD Audio Controller [8086:284b] (rev 02)
        Subsystem: Dell Device [1028:0209]
        Kernel driver in use: HDA Intel
        Kernel modules: snd-hda-intel

-----

marc@XPS:~$ speaker-test -c6 -D surround51 

speaker-test 1.0.24.2

Playback device is surround51
Stream parameters are 48000Hz, S16_LE, 6 channels
Using 16 octaves of pink noise
Channels count (6) not available for playbacks: Invalid argument
Setting of hwparams failed: Invalid argument

-----

marc@XPS:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: STAC92xx Analog [STAC92xx Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: STAC92xx Digital [STAC92xx Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

-----

marc@XPS:~$ aplay -L
default
    Playback/recording through the PulseAudio sound server
pulse
    Playback/recording through the PulseAudio sound server
front:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    Front speakers
surround40:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    4.0 Surround output to Front and Rear speakers
surround41:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Digital
    IEC958 (S/PDIF) Digital Audio Output
hdmi:CARD=Intel,DEV=0
    HDA Intel, HDMI 0
    HDMI Audio Output
dmix:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    Direct sample mixing device
dmix:CARD=Intel,DEV=1
    HDA Intel, STAC92xx Digital
    Direct sample mixing device
dmix:CARD=Intel,DEV=3
    HDA Intel, HDMI 0
    Direct sample mixing device
dsnoop:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    Direct sample snooping device
dsnoop:CARD=Intel,DEV=1
    HDA Intel, STAC92xx Digital
    Direct sample snooping device
dsnoop:CARD=Intel,DEV=3
    HDA Intel, HDMI 0
    Direct sample snooping device
hw:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    Direct hardware device without any conversions
hw:CARD=Intel,DEV=1
    HDA Intel, STAC92xx Digital
    Direct hardware device without any conversions
hw:CARD=Intel,DEV=3
    HDA Intel, HDMI 0
    Direct hardware device without any conversions
plughw:CARD=Intel,DEV=0
    HDA Intel, STAC92xx Analog
    Hardware device with all software conversions
plughw:CARD=Intel,DEV=1
    HDA Intel, STAC92xx Digital
    Hardware device with all software conversions
plughw:CARD=Intel,DEV=3
    HDA Intel, HDMI 0
    Hardware device with all software conversions

-----

marc@XPS:~$ cat /etc/pulse/daemon.conf 
# This file is part of PulseAudio.
#
# PulseAudio is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# PulseAudio is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with PulseAudio; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
# USA.

## Configuration file for the PulseAudio daemon. See pulse-daemon.conf(5) for
## more information. Default values a commented out.  Use either ; or # for
## commenting.

; daemonize = no
; fail = yes
; allow-module-loading = yes
; allow-exit = yes
; use-pid-file = yes
; system-instance = no
; enable-shm = yes
; shm-size-bytes = 0 # setting this 0 will use the system-default, usually 64 MiB
; lock-memory = no
; cpu-limit = no

; high-priority = yes
; nice-level = -11

; realtime-scheduling = yes
; realtime-priority = 5

; exit-idle-time = 20
; scache-idle-time = 20

; dl-search-path = (depends on architecture)

; load-default-script-file = yes
; default-script-file = 

; log-target = auto
; log-level = notice
; log-meta = no
; log-time = no
; log-backtrace = 0

resample-method = speex-float-1
; enable-remixing = yes
; enable-lfe-remixing = no

flat-volumes = no

; rlimit-fsize = -1
; rlimit-data = -1
; rlimit-stack = -1
; rlimit-core = -1
; rlimit-as = -1
; rlimit-rss = -1
; rlimit-nproc = -1
; rlimit-nofile = 256
; rlimit-memlock = -1
; rlimit-locks = -1
; rlimit-sigpending = -1
; rlimit-msgqueue = -1
; rlimit-nice = 31
; rlimit-rtprio = 9
; rlimit-rttime = 1000000

; default-sample-format = s16le
; default-sample-rate = 44100
; default-sample-channels = 6
; default-channel-map = front-left,front-right

default-fragments = 8
default-fragment-size-msec = 10