[PROBLEM] Upmix Stereo Signal to play on all speakers of a 5.1 system

[MichelGauss]

........snip................... My problem: I'm using a 5.1 Audio card (Creative Sound Blaster X-Fi USB) and a corresponding speaker set. Installing it worked like a charm and out of the box, however, since the system is a 5.1 system, audio is only played on three speaker (left+right and bass) but I would love to have stereo sound automatically upmixed so that it plays on all 6 speakers at the same time.
It seems that there is no corresponding function in Moode audio, at least I haven't found one. A solution would be to manually edit the ALSA configuration, however I don't think that this is a good idea and would definitivly prefer to have an "integrated" solution. Any ideas? ...........snip...........................

Honestly I'm not sure that this is a 'problem' as there's no point of playing 'stereo sound' through a 5.1 speaker system without detracting from the quality of the sound... the 'timing and soundstage' mentioned by @vinn will be affected by the audio waves cancelling each other in the middle area of the speaker set-up. The sound would need to be 'edited' hence waving 'goodbye' to the conception of 'bitperfect playback'... IMHO

Thanks for telling me that my problem isn't a problem at all.  

I appreciate the discussions in this forum, and I understand that some people don't want upmixing due to possible inferences etc. And I understand that from the point of view of some people doing something like upmixing is really really bad and should not be added to moode. Ok, discuss that. I can live with an answer like: "we won't include it, due to missunderstandings/complains for bad audio etc..." or not enough demand.

However, what really offended me here is the fact that I'm asking a questions on HOW TO do something. Telling me then, that I do not need to do something becasue you won't do it and that there are "no reasons to do it", is at least impolite. I asked for it, so you might assume that I have a reason for it. Especially in an area like audio and music that is highly subjective. In fact, I had it already using it with the same hardware, same room, but different software.

Back to less emotional reasons, here is one of my reasons for upmixing: My daughter using the system to listen to stories, however she don't want to sit a specific area in the room. So when she's further away from the two "working" speakers, she needs the volume higher to be able to understand what the people are saying. However, that is not always compatible with the other people in the room....