For sanity I just share the relevant parts of my system.pa
#### I do this by hand for the remaps
# ### Automatically load driver modules depending on the hardware available
# .ifexists module-hal-detect.so
# load-module module-hal-detect
# .else
# ### Alternatively use the static hardware detection module (for systems that
# ### lack HAL support)
# load-module module-detect
#.endif
### Automatically suspend sinks/sources that become idle for too long
#load-module module-suspend-on-idle
#bug: http://pulseaudio.org/ticket/326
# Set the speakers as the default device
set-default-sink speakers
# Map device 0 to sound_card (this is my sound card) and use 4 channels
load-module module-alsa-sink sink_name=sound_card device_id=0 channels=4 channel_map=front-left,front-right,rear-left,rear-right
# Map the front channels to the speakers sink
load-module module-remap-sink sink_name=speakers master=sound_card channels=2 master_channel_map=front-left,front-right channel_map=front-left,front-right
# Map the rear channels to the headphones sink
load-module module-remap-sink sink_name=headphones master=sound_card channels=2 master_channel_map=rear-left,rear-right channel_map=front-left,front-right
And here's what I changed in daemon.conf:
;make channel-splitting work (may destroy mono to stereo on mono files)
disable-remixing = yes
default-sample-channels = 4
Unfortunately the sink names are not shown in PulseAudio Volume Control but some trial and error (choosing 1 out of to 2 :P) will tell you which sink is the speakers and which is the headphones.