Using a Cambridge Soundworks Desktop Theater 5.1 DTT2200 sound systems with my PC (Windows 7).
Set up all speakers and check that they are all working at the system level
Instructions to set VLC media player to play through all speakers as follows:
Open VLC preferences (Tools…Preferences) and under the “Show settings” section, select All.
Under the Audio section expand the Output modules section and select DirectX (or Dolby Digital)
Pick the output device you’re using, which has been set up for 5.1 sound, and specify the Speaker configuration as 5.1
Save the preferences and restart the VLC player. Audio will be played using all the speakers.
VLC media player
VLC is a free and open source cross-platform multimedia player and framework that plays most multimedia files as well as DVDs, Audio CDs, VCDs, and various streaming protocols.
User guide available
DTT2200 User Guide (pdf)