How do I create or convert a WAV file to play only with rear speakers. What Windows/Linux software could I use to do that?
I tried to use Audacity but with no results.
A standard .WAV file can contain multiple channels, but there is no universal mapping of channels to speakers. So you will need to know something about the playback system to target the rear speakers only.
If your target system is 5.1, you might get away with creating a 6 channel file, and only putting your data in the 5th and 6th channels. See this page on "Multiple Channel Audio Data and WAVE Files".
Another way might to use Dolby Pro Logic Encoding - many players support this format. In that case your output file is a 2-channel stereo wave file.
If you need this for setup- / testing purposes, I suggest using
These two pages may also be useful:
A Google-search found this list of free audio editors, some of them supporting multi-channel editing (e.g. "Eisenkraut", #14 in the list):
For playing back a multichannel audio file, you may need other than mainstream media players. I see