Downloaded your RRConfig, ran it, made some simple changes, and saved.
AND DigitalFX works just fine up to the point that I am missing some bits that I will look into tomorrow.
P.S. For the sake of knowledge, what dioes GDI refer to?
Graphics Device Interface
I found that only programs that use DirectSound for output play through all my speakers
windows itself doesn't use it that's why the sounds in windows like startup & shutdown etc.. only play in the front speakers
But games of course use it so all speakers work
A lot of that depends on how you have your sound set up. Quite a number of sound cards don't handle multi-channel audio well. One particular card had a noticeable delay between the front and back speakers with the 4-channel emulation it used.