There are many people who own creative gear who can chime in (I don't have one), but I'm pretty sure sbx surround is creative's vss technology. In this context, vss being the use of hrtf to maintain the spatial information in a surround sound mix.
look man, i also owned different creative cards for the last 20 years or so, like a lot of people here.
i'm telling you how it works specifically with g6, with it's current driver and firmware (on today's beta now).
its stupidly easy to turn off sbx surround but leave 7.1 and do windows mmsys.cpl test.
without sbx surround it sound less spacious but there are still directional cues.
what is also unfortunate is that they are worse than x-fi cmss 3d regardless of the settings i use with g6.
fortunately g6 + hesuvi gsx is good so i think the card will stay with me.