I have just upgraded to 12.10 from 12.04LTS, I was just configuring the sound for 5.1 and have found out that not all the speakers seem to be receiving a single to produce sound.
I have seen that if I configure the sound on Ubuntu to 7.1 the and test the speakers; what is the rear right and left play for side left and right
Would post images but can't on this forum yet
EDIT: this is my output for aplay -l
**** List of PLAYBACK Hardware Devices **** card 0: Intel [HDA Intel], device 0: ALC889 Analog [ALC889 Analog] Subdevices: 0/1 Subdevice #0: subdevice #0 card 0: Intel [HDA Intel], device 1: ALC889 Digital [ALC889 Digital] Subdevices: 1/1 Subdevice #0: subdevice #0